https://www.cazypedia.org/api.php?action=feedcontributions&feedformat=atom&user=Tirso+PonsCAZypedia - User contributions [en-ca]2026-05-25T13:35:40ZUser contributionsMediaWiki 1.35.10https://www.cazypedia.org/index.php?title=File:Tirso-03.jpg&diff=8797File:Tirso-03.jpg2013-06-08T22:00:27Z<p>Tirso Pons: Tirso Pons uploaded a new version of &quot;File:Tirso-03.jpg&quot;</p>
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<div></div>Tirso Ponshttps://www.cazypedia.org/index.php?title=File:Tirso-03.jpg&diff=8796File:Tirso-03.jpg2013-06-08T21:56:27Z<p>Tirso Pons: Tirso Pons uploaded a new version of &quot;File:Tirso-03.jpg&quot;</p>
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<div></div>Tirso Ponshttps://www.cazypedia.org/index.php?title=User:Tirso_Pons&diff=8795User:Tirso Pons2013-06-08T21:52:02Z<p>Tirso Pons: </p>
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<div>[[File:Tirso-03.jpg|200px|right]]<br />
'''Tirso Pons''' obtained his B.Sc. degree in Nuclear Physics from the Institute of Nuclear Sciences, Havana, then completed his Ph.D. in Biology at University of Havana with Joaquin Diaz and Alfonso Valencia in 2002, working on the sequence analysis, and structure and functional residues prediction for glycoside hydrolase [[GH32]], [[GH49]] and [[GH68]] families. He and colleagues predicted for the first time a common beta-propeller fold for the catalytic domain in [[GH32]] and [[GH68]] families, and also proposed the aspartate residue in the conserved "Arg-Asp-Pro (RDP) motif" as a third residue important for catalysis. Through collaboration with Prof. ^^^Gideon Davies^^^ (York University, UK), he and colleagues determined the crystal structure of levansucrase from the gram-negative bacterium ''Gluconacetobacter diazotrophicus'' SRT4. Tirso was a visiting scientist at Dr. Alfonso Valencia's Lab (CNB-CSIC) at the Autonomous University of Madrid, Spain, and at Dr. Gert Vriend's lab at the European Molecular Biology Laboratory (EMBL), Heidelberg, Germany.<br />
In 2007 and 2010 he obtained postdoctoral SEBiot and EMBO fellowships at the Structural Biology and Biocomputing Programme of the Spanish National Cancer Research Centre (CNIO), Madrid. From 2006 to 2011, he was an Associate Professor at Deparment of Biochemistry, and permanent researcher at the Center for Protein Research (CEP), Faculty of Biology, University of Havana. He is currently a staff scientists in the Structural Computational Biology Group within the Structural Biology and Biocomputing Programme at CNIO.<br />
More details are available at the web sites [http://www.researcherid.com/rid/A-6377-2011] or [http://es.linkedin.com/pub/tirso-pons/70/661/bb7/]<br />
[[Category:Contributors|Pons,Tirso]]</div>Tirso Ponshttps://www.cazypedia.org/index.php?title=Glycoside_Hydrolase_Family_68&diff=8002Glycoside Hydrolase Family 682012-12-14T22:25:10Z<p>Tirso Pons: </p>
<hr />
<div><!-- CURATORS: Please replace the {{UnderConstruction}} tag below with {{CuratorApproved}} when the page is ready for wider public consumption --><br />
{{CuratorApproved}}<br />
* [[Author]]: ^^^Tirso Pons^^^ and ^^^Wim Van den Ende^^^<br />
* [[Responsible Curator]]: ^^^Wim Van den Ende^^^<br />
----<br />
<br />
<!-- The data in the table below should be updated by the Author/Curator according to current information on the family --><br />
<div style="float:right"><br />
{| {{Prettytable}} <br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH68'''<br />
|-<br />
|'''Clan''' <br />
|GH-J<br />
|-<br />
|'''Mechanism'''<br />
|retaining<br />
|-<br />
|'''Active site residues'''<br />
|known<br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br />
|-<br />
| colspan="2" |{{CAZyDBlink}}GH68.html<br />
|}<br />
</div><br />
<!-- This is the end of the table --><br />
<br />
<br />
== Substrate specificities ==<br />
[[Glycoside hydrolase]] family 68 enzymes include levansucrase (sucrose:2,6-β-D-fructan 6-β-D-fructosyltransferase; EC [{{EClink}}2.4.1.10 2.4.1.10]), β-fructofuranosidase (EC [{{EClink}}3.2.1.26 3.2.1.26]), and inulosucrase (EC [{{EClink}}2.4.1.9 2.4.1.9]). All these enzymes use sucrose as their preferential donor substrate. Many of them can create very long levan-type fructans (catalyzed by levansucrases) or inulin-type of fructans (catalyzed by inulosucrases), as well as fructooligosacharides (FOS). However, some GH68 enzymes can also use fructan as donor substrate (in the abscence of sucrose or at a high fructan/sucrose ratio). <br />
<br />
== Kinetics and Mechanism ==<br />
Family GH68 enzymes as well as those included in [[GH32]] are [[retaining]] enzymes <cite>Koshland1954</cite>. The levansucrases from ''Bacillus subtilis'', ''Gluconacetobacter diazotrophicus'', and ''Streptococcus salivarius'' catalyze transfructosylation via a ping-pong mechanism involving the formation of a transient fructosyl-enzyme intermediate <cite>Chambert1974 Cambert1976 Hernandez1995 Song1999</cite>. At low sucrose concentrations levansucrase functions as a hydrolase with water as acceptor, whereas at higher substrate concentrations it adds fructosyl units to a variety of acceptors including glucose, fructan and sucrose <cite>Chambert1974</cite>. Bacterial levansucrases, whatever their origin, catalyze all these reactions but with different efficiency.<br />
<br />
== Catalytic Residues ==<br />
GH68 [[retaining]] enzymes catalyze hydrolysis in two steps involving a covalent glycosyl enzyme [[intermediate]]. The two invariant residues, responsible for the catalytic reaction in family GH68 enzymes, have first been identified experimentally in bacterial levansucrases as an aspartate located close to the N-terminus acting as the [[catalytic nucleophile]] and a glutamate acting as the [[general acid/base]] <cite>Meng2003 Yanase2002</cite>. In addition, a conserved aspartate residue in the "Arg-Asp-Pro (RDP) motif" stabilizes the [[transition state]] <cite>Song1999 Yanase2002 Batista1999</cite>. The three equivalent acidic residues have been mutated in a β-fructofuranosidase from ''Arthrobacter globiformis'' IFO 3062 <cite>Isono2004</cite>, and in a levansucrase and a inulosucrase from ''Lactobacillus reuteri'' 121 <cite>Ozimek2004</cite>.<br />
<br />
== Three-dimensional structures ==<br />
Currently, only five different three dimensional structures of family GH68 enzymes have been solved. The first crystal structure was reported for the bacterial levansucrase (SacB) from ''Bacillus subtilis'' subsp. subtilis str. 168 <cite>Meng2003</cite>. The second one corresponds to levansucrase (LdsA) from ''Gluconacetobacter diazotrophicus'' SRT4 <cite>MartinezFleites2005</cite>, the third corresponds to SacB from ''Bacillus megaterium'' <cite>Strube2011</cite>, the four is an inulosucrase (InuJ) from ''Lactobacillus johnsonii'' NCC533 <cite>Pijning2011</cite>, and the last one corresponds to beta-fructofuranosidase (ArFFase) from Arthrobacter sp. K-1 <cite>Tonozuca2012</cite>. These structures display a 5-fold β-propeller topology, and therefore GH families 68 and [[GH32|32]] have been combined in clan GH-J. On the other hand, a structural relationship of the catalytic core exists to family GH68 and family [[GH43]], as predicted by detailed sequence analysis<cite>Naumoff2001</cite>.<br />
<br />
== Family Firsts ==<br />
;First stereochemistry determination: ''Bacillus subtilis'' levansucrase <cite>Chambert1974</cite>.<br />
;First [[catalytic nucleophile]] identification: ''Bacillus subtilis'' levansucrase <cite>Meng2003</cite>.<br />
;First [[general acid/base]] residue identification: ''Zymomonas mobilis'' levansucrase <cite>Yanase2002</cite>.<br />
;First stabilizing [[transition state]] residue identification: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>Batista1999</cite>.<br />
;First prediction of a common beta-propeller catalytic domain in GH68 / clan GH-J: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>Pons1998 Pons2000</cite>.<br />
;First 3-D structure: ''Bacillus subtilis'' levansucrase <cite>Meng2003</cite>.<br />
<br />
== References ==<br />
<biblio><br />
#Koshland1954 pmid=13174523<br />
#Chambert1974 pmid=4206083<br />
#Chambert1976 pmid=814002<br />
#Hernandez1995 pmid=7619044<br />
#Song1999 pmid=10393084<br />
#Meng2003 pmid=14517548<br />
#Yanase2002 pmid=12359071<br />
#Batista1999 pmid=9895294<br />
#Isono2004 pmid=16233623<br />
#Ozimek2004 pmid=14988011<br />
#MartinezFleites2005 pmid=15869470<br />
#Naumoff2001 pmid=11093261<br />
#Pons1998 pmid=9829697<br />
#Pons2000 pmid=11305239<br />
#Strube2011 pmid=21454585<br />
#Pijning2011 pmid=21801732<br />
#Tonozuca2012 pmid=23040392<br />
</biblio><br />
<br />
<br />
[[Category:Glycoside Hydrolase Families|GH068]]</div>Tirso Ponshttps://www.cazypedia.org/index.php?title=Glycoside_Hydrolase_Family_68&diff=6978Glycoside Hydrolase Family 682011-09-17T08:34:52Z<p>Tirso Pons: </p>
<hr />
<div><!-- CURATORS: Please replace the {{UnderConstruction}} tag below with {{CuratorApproved}} when the page is ready for wider public consumption --><br />
{{CuratorApproved}}<br />
* [[Author]]: ^^^Tirso Pons^^^ and ^^^Wim Van den Ende^^^<br />
* [[Responsible Curator]]: ^^^Wim Van den Ende^^^<br />
----<br />
<br />
<!-- The data in the table below should be updated by the Author/Curator according to current information on the family --><br />
<div style="float:right"><br />
{| {{Prettytable}} <br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH68'''<br />
|-<br />
|'''Clan''' <br />
|GH-J<br />
|-<br />
|'''Mechanism'''<br />
|retaining<br />
|-<br />
|'''Active site residues'''<br />
|known<br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br />
|-<br />
| colspan="2" |http://www.cazy.org/fam/GH68.html<br />
|}<br />
</div><br />
<!-- This is the end of the table --><br />
<br />
<br />
== Substrate specificities ==<br />
[[Glycoside hydrolase]] family 68 enzymes include levansucrase (sucrose:2,6-β-D-fructan 6-β-D-fructosyltransferase; EC [{{EClink}}2.4.1.10 2.4.1.10]), β-fructofuranosidase (EC [{{EClink}}3.2.1.26 3.2.1.26]), and inulosucrase (EC [{{EClink}}2.4.1.9 2.4.1.9]). All these enzymes use sucrose as their preferential donor substrate. Many of them can create very long levan-type fructans (catalyzed by levansucrases) or inulin-type of fructans (catalyzed by inulosucrases), as well as fructooligosacharides (FOS). However, some GH68 enzymes can also use fructan as donor substrate (in the abscence of sucrose or at a high fructan/sucrose ratio). <br />
<br />
== Kinetics and Mechanism ==<br />
Family GH68 enzymes as well as those included in [[GH32]] are [[retaining]] enzymes <cite>Koshland1954</cite>. The levansucrases from ''Bacillus subtilis'', ''Gluconacetobacter diazotrophicus'', and ''Streptococcus salivarius'' catalyze transfructosylation via a ping-pong mechanism involving the formation of a transient fructosyl-enzyme intermediate <cite>Chambert1974 Cambert1976 Hernandez1995 Song1999</cite>. At low sucrose concentrations levansucrase functions as a hydrolase with water as acceptor, whereas at higher substrate concentrations it adds fructosyl units to a variety of acceptors including glucose, fructan and sucrose <cite>Chambert1974</cite>. Bacterial levansucrases, whatever their origin, catalyze all these reactions but with different efficiency.<br />
<br />
== Catalytic Residues ==<br />
GH68 [[retaining]] enzymes catalyze hydrolysis in two steps involving a covalent glycosyl enzyme [[intermediate]]. The two invariant residues, responsible for the catalytic reaction in family GH68 enzymes, have first been identified experimentally in bacterial levansucrases as an aspartate located close to the N-terminus acting as the [[catalytic nucleophile]] and a glutamate acting as the [[general acid/base]] <cite>Meng2003 Yanase2002</cite>. In addition, a conserved aspartate residue in the "Arg-Asp-Pro (RDP) motif" stabilizes the [[transition state]] <cite>Song1999 Yanase2002 Batista1999</cite>. The three equivalent acidic residues have been mutated in a β-fructofuranosidase from ''Arthrobacter globiformis'' IFO 3062 <cite>Isono2004</cite>, and in a levansucrase and a inulosucrase from ''Lactobacillus reuteri'' 121 <cite>Ozimek2004</cite>.<br />
<br />
== Three-dimensional structures ==<br />
Currently, only four different three dimensional structures of family GH68 enzymes have been solved. The first crystal structure was reported for the bacterial levansucrase (SacB) from ''Bacillus subtilis'' subsp. subtilis str. 168 <cite>Meng2003</cite>. The second one corresponds to levansucrase (LdsA) from ''Gluconacetobacter diazotrophicus'' SRT4 <cite>MartinezFleites2005</cite>, the third corresponds to SacB from ''Bacillus megaterium'' <cite>Strube2011</cite>, and the last one corresponds to inulosucrase (InuJ) from ''Lactobacillus johnsonii'' NCC533 <cite>Pijning2011</cite>. These structures display a 5-fold β-propeller topology, and therefore GH families 68 and [[GH32|32]] have been combined in clan GH-J. On the other hand, a structural relationship of the catalytic core exists to family GH68 and family [[GH43]], as predicted by detailed sequence analysis<cite>Naumoff2001</cite>.<br />
<br />
== Family Firsts ==<br />
;First stereochemistry determination: ''Bacillus subtilis'' levansucrase <cite>Chambert1974</cite>.<br />
;First [[catalytic nucleophile]] identification: ''Bacillus subtilis'' levansucrase <cite>Meng2003</cite>.<br />
;First [[general acid/base]] residue identification: ''Zymomonas mobilis'' levansucrase <cite>Yanase2002</cite>.<br />
;First stabilizing [[transition state]] residue identification: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>Batista1999</cite>.<br />
;First prediction of a common beta-propeller catalytic domain in GH68 / clan GH-J: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>Pons1998 Pons2000</cite>.<br />
;First 3-D structure: ''Bacillus subtilis'' levansucrase <cite>Meng2003</cite>.<br />
<br />
== References ==<br />
<biblio><br />
#Koshland1954 pmid=13174523<br />
#Chambert1974 pmid=4206083<br />
#Chambert1976 pmid=814002<br />
#Hernandez1995 pmid=7619044<br />
#Song1999 pmid=10393084<br />
#Meng2003 pmid=14517548<br />
#Yanase2002 pmid=12359071<br />
#Batista1999 pmid=9895294<br />
#Isono2004 pmid=16233623<br />
#Ozimek2004 pmid=14988011<br />
#MartinezFleites2005 pmid=15869470<br />
#Naumoff2001 pmid=11093261<br />
#Pons1998 pmid=9829697<br />
#Pons2000 pmid=11305239<br />
#Strube2011 pmid=21454585<br />
#Pijning2011 pmid=21801732<br />
</biblio><br />
<br />
<br />
[[Category:Glycoside Hydrolase Families|GH068]]</div>Tirso Ponshttps://www.cazypedia.org/index.php?title=Glycoside_Hydrolase_Family_68&diff=6951Glycoside Hydrolase Family 682011-08-18T08:29:31Z<p>Tirso Pons: </p>
<hr />
<div><!-- CURATORS: Please replace the {{UnderConstruction}} tag below with {{CuratorApproved}} when the page is ready for wider public consumption --><br />
{{CuratorApproved}}<br />
* [[Author]]: ^^^Tirso Pons^^^ and ^^^Wim Van den Ende^^^<br />
* [[Responsible Curator]]: ^^^Wim Van den Ende^^^<br />
----<br />
<br />
<!-- The data in the table below should be updated by the Author/Curator according to current information on the family --><br />
<div style="float:right"><br />
{| {{Prettytable}} <br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH68'''<br />
|-<br />
|'''Clan''' <br />
|GH-J<br />
|-<br />
|'''Mechanism'''<br />
|retaining<br />
|-<br />
|'''Active site residues'''<br />
|known<br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br />
|-<br />
| colspan="2" |http://www.cazy.org/fam/GH68.html<br />
|}<br />
</div><br />
<!-- This is the end of the table --><br />
<br />
<br />
== Substrate specificities ==<br />
[[Glycoside hydrolase]] family 68 enzymes include levansucrase (sucrose:2,6-β-D-fructan 6-β-D-fructosyltransferase; EC [{{EClink}}2.4.1.10 2.4.1.10]), β-fructofuranosidase (EC [{{EClink}}3.2.1.26 3.2.1.26]), and inulosucrase (EC [{{EClink}}2.4.1.9 2.4.1.9]). All these enzymes use sucrose as their preferential donor substrate. Many of them can create very long levan-type fructans (catalyzed by levansucrases) or inulin-type of fructans (catalyzed by inulosucrases), as well as fructooligosacharides (FOS). However, some GH68 enzymes can also use fructan as donor substrate (in the abscence of sucrose or at a high fructan/sucrose ratio). <br />
<br />
== Kinetics and Mechanism ==<br />
Family GH68 enzymes as well as those included in [[GH32]] are [[retaining]] enzymes <cite>Koshland1954</cite>. The levansucrases from ''Bacillus subtilis'', ''Gluconacetobacter diazotrophicus'', and ''Streptococcus salivarius'' catalyze transfructosylation via a ping-pong mechanism involving the formation of a transient fructosyl-enzyme intermediate <cite>Chambert1974 Cambert1976 Hernandez1995 Song1999</cite>. At low sucrose concentrations levansucrase functions as a hydrolase with water as acceptor, whereas at higher substrate concentrations it adds fructosyl units to a variety of acceptors including glucose, fructan and sucrose <cite>Chambert1974</cite>. Bacterial levansucrases, whatever their origin, catalyze all these reactions but with different efficiency.<br />
<br />
== Catalytic Residues ==<br />
GH68 [[retaining]] enzymes catalyze hydrolysis in two steps involving a covalent glycosyl enzyme [[intermediate]]. The two invariant residues, responsible for the catalytic reaction in family GH68 enzymes, have first been identified experimentally in bacterial levansucrases as an aspartate located close to the N-terminus acting as the [[catalytic nucleophile]] and a glutamate acting as the [[general acid/base]] <cite>Meng2003 Yanase2002</cite>. In addition, a conserved aspartate residue in the "Arg-Asp-Pro (RDP) motif" stabilizes the [[transition state]] <cite>Song1999 Yanase2002 Batista1999</cite>. The three equivalent acidic residues have been mutated in a β-fructofuranosidase from ''Arthrobacter globiformis'' IFO 3062 <cite>Isono2004</cite>, and in a levansucrase and a inulosucrase from ''Lactobacillus reuteri'' 121 <cite>Ozimek2004</cite>.<br />
<br />
== Three-dimensional structures ==<br />
Currently, only three different three dimensional structures of family GH68 enzymes have been solved. The first crystal structure was reported for the bacterial levansucrase (SacB) from ''Bacillus subtilis'' subsp. subtilis str. 168 <cite>Meng2003</cite>. The second one corresponds to levansucrase (LdsA) from ''Gluconacetobacter diazotrophicus'' SRT4 <cite>MartinezFleites2005</cite>, and the last one corresponds to SacB from ''Bacillus megaterium'' <cite>Strube2011</cite>. These structures display a 5-fold β-propeller topology, and therefore GH families 68 and [[GH32|32]] have been combined in clan GH-J. On the other hand, a structural relationship of the catalytic core exists to family GH68 and family [[GH43]], as predicted by detailed sequence analysis<cite>Naumoff2001</cite>.<br />
<br />
== Family Firsts ==<br />
;First stereochemistry determination: ''Bacillus subtilis'' levansucrase <cite>Chambert1974</cite>.<br />
;First [[catalytic nucleophile]] identification: ''Bacillus subtilis'' levansucrase <cite>Meng2003</cite>.<br />
;First [[general acid/base]] residue identification: ''Zymomonas mobilis'' levansucrase <cite>Yanase2002</cite>.<br />
;First stabilizing [[transition state]] residue identification: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>Batista1999</cite>.<br />
;First prediction of a common beta-propeller catalytic domain in GH68 / clan GH-J: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>Pons1998 Pons2000</cite>.<br />
;First 3-D structure: ''Bacillus subtilis'' levansucrase <cite>Meng2003</cite>.<br />
<br />
== References ==<br />
<biblio><br />
#Koshland1954 pmid=13174523<br />
#Chambert1974 pmid=4206083<br />
#Chambert1976 pmid=814002<br />
#Hernandez1995 pmid=7619044<br />
#Song1999 pmid=10393084<br />
#Meng2003 pmid=14517548<br />
#Yanase2002 pmid=12359071<br />
#Batista1999 pmid=9895294<br />
#Isono2004 pmid=16233623<br />
#Ozimek2004 pmid=14988011<br />
#MartinezFleites2005 pmid=15869470<br />
#Naumoff2001 pmid=11093261<br />
#Pons1998 pmid=9829697<br />
#Pons2000 pmid=11305239<br />
#Strube2011 pmid=21454585<br />
</biblio><br />
<br />
<br />
[[Category:Glycoside Hydrolase Families|GH068]]</div>Tirso Ponshttps://www.cazypedia.org/index.php?title=Glycoside_Hydrolase_Family_68&diff=6950Glycoside Hydrolase Family 682011-08-18T08:03:10Z<p>Tirso Pons: </p>
<hr />
<div><!-- CURATORS: Please replace the {{UnderConstruction}} tag below with {{CuratorApproved}} when the page is ready for wider public consumption --><br />
{{CuratorApproved}}<br />
* [[Author]]: ^^^Tirso Pons^^^ and ^^^Wim Van den Ende^^^<br />
* [[Responsible Curator]]: ^^^Wim Van den Ende^^^<br />
----<br />
<br />
<!-- The data in the table below should be updated by the Author/Curator according to current information on the family --><br />
<div style="float:right"><br />
{| {{Prettytable}} <br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH68'''<br />
|-<br />
|'''Clan''' <br />
|GH-J<br />
|-<br />
|'''Mechanism'''<br />
|retaining<br />
|-<br />
|'''Active site residues'''<br />
|known<br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br />
|-<br />
| colspan="2" |http://www.cazy.org/fam/GH68.html<br />
|}<br />
</div><br />
<!-- This is the end of the table --><br />
<br />
<br />
== Substrate specificities ==<br />
[[Glycoside hydrolase]] family 68 enzymes include levansucrase (sucrose:2,6-β-D-fructan 6-β-D-fructosyltransferase; EC [{{EClink}}2.4.1.10 2.4.1.10]), β-fructofuranosidase (EC [{{EClink}}3.2.1.26 3.2.1.26]), and inulosucrase (EC [{{EClink}}2.4.1.9 2.4.1.9]). All these enzymes use sucrose as their preferential donor substrate. Many of them can create very long levan-type fructans (catalyzed by levansucrases) or inulin-type of fructans (catalyzed by inulosucrases), as well as fructooligosacharides (FOS). However, some GH68 enzymes can also use fructan as donor substrate (in the abscence of sucrose or at a high fructan/sucrose ratio). <br />
<br />
== Kinetics and Mechanism ==<br />
Family GH68 enzymes as well as those included in [[GH32]] are [[retaining]] enzymes <cite>Koshland1954</cite>. The levansucrases from ''Bacillus subtilis'', ''Gluconacetobacter diazotrophicus'', and ''Streptococcus salivarius'' catalyze transfructosylation via a ping-pong mechanism involving the formation of a transient fructosyl-enzyme intermediate <cite>2 3 4 5</cite>. At low sucrose concentrations levansucrase functions as a hydrolase with water as acceptor, whereas at higher substrate concentrations it adds fructosyl units to a variety of acceptors including glucose, fructan and sucrose <cite>2</cite>. Bacterial levansucrases, whatever their origin, catalyze all these reactions but with different efficiency.<br />
<br />
== Catalytic Residues ==<br />
GH68 [[retaining]] enzymes catalyze hydrolysis in two steps involving a covalent glycosyl enzyme [[intermediate]]. The two invariant residues, responsible for the catalytic reaction in family GH68 enzymes, have first been identified experimentally in bacterial levansucrases as an aspartate located close to the N-terminus acting as the [[catalytic nucleophile]] and a glutamate acting as the [[general acid/base]] <cite>6 7</cite>. In addition, a conserved aspartate residue in the "Arg-Asp-Pro (RDP) motif" stabilizes the [[transition state]] <cite>5 7 8</cite>. The three equivalent acidic residues have been mutated in a β-fructofuranosidase from ''Arthrobacter globiformis'' IFO 3062 <cite>9</cite>, and in a levansucrase and a inulosucrase from ''Lactobacillus reuteri'' 121 <cite>10</cite>.<br />
<br />
== Three-dimensional structures ==<br />
Currently, only three different three dimensional structures of family GH68 enzymes have been solved. The first crystal structure was reported for the bacterial levansucrase (SacB) from ''Bacillus subtilis'' subsp. subtilis str. 168 <cite>6</cite>. The second one corresponds to levansucrase (LdsA) from ''Gluconacetobacter diazotrophicus'' SRT4 <cite>11</cite>, and the last one corresponds to SacB from ''Bacillus megaterium'' <cite>15</cite>. These structures display a 5-fold β-propeller topology, and therefore GH families 68 and [[GH32|32]] have been combined in clan GH-J. On the other hand, a structural relationship of the catalytic core exists to family GH68 and family [[GH43]], as predicted by detailed sequence analysis<cite>12</cite>.<br />
<br />
== Family Firsts ==<br />
;First stereochemistry determination: ''Bacillus subtilis'' levansucrase <cite>2</cite>.<br />
;First [[catalytic nucleophile]] identification: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
;First [[general acid/base]] residue identification: ''Zymomonas mobilis'' levansucrase <cite>7</cite>.<br />
;First stabilizing [[transition state]] residue identification: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>11</cite>.<br />
;First prediction of a common beta-propeller catalytic domain in GH68 / clan GH-J: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>13 14</cite>.<br />
;First 3-D structure: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
<br />
== References ==<br />
<biblio><br />
#Koshland1954 pmid=13174523<br />
#2 pmid=4206083<br />
#3 pmid=814002<br />
#4 pmid=7619044<br />
#5 pmid=10393084<br />
#6 pmid=14517548<br />
#7 pmid=12359071<br />
#8 pmid=9895294<br />
#9 pmid=16233623<br />
#10 pmid=14988011<br />
#11 pmid=15869470<br />
#12 pmid=11093261<br />
#13 pmid=9829697<br />
#14 pmid=11305239<br />
#15 pmid=21454585<br />
</biblio><br />
<br />
<br />
[[Category:Glycoside Hydrolase Families|GH068]]</div>Tirso Ponshttps://www.cazypedia.org/index.php?title=Glycoside_Hydrolase_Family_68&diff=6949Glycoside Hydrolase Family 682011-08-02T17:34:11Z<p>Tirso Pons: </p>
<hr />
<div><!-- CURATORS: Please replace the {{UnderConstruction}} tag below with {{CuratorApproved}} when the page is ready for wider public consumption --><br />
{{CuratorApproved}}<br />
* [[Author]]: ^^^Tirso Pons^^^ and ^^^Wim Van den Ende^^^<br />
* [[Responsible Curator]]: ^^^Wim Van den Ende^^^<br />
----<br />
<br />
<!-- The data in the table below should be updated by the Author/Curator according to current information on the family --><br />
<div style="float:right"><br />
{| {{Prettytable}} <br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH68'''<br />
|-<br />
|'''Clan''' <br />
|GH-J<br />
|-<br />
|'''Mechanism'''<br />
|retaining<br />
|-<br />
|'''Active site residues'''<br />
|known<br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br />
|-<br />
| colspan="2" |http://www.cazy.org/fam/GH68.html<br />
|}<br />
</div><br />
<!-- This is the end of the table --><br />
<br />
<br />
== Substrate specificities ==<br />
[[Glycoside hydrolase]] family 68 enzymes include levansucrase (sucrose:2,6-β-D-fructan 6-β-D-fructosyltransferase; EC [{{EClink}}2.4.1.10 2.4.1.10]), β-fructofuranosidase (EC [{{EClink}}3.2.1.26 3.2.1.26]), and inulosucrase (EC [{{EClink}}2.4.1.9 2.4.1.9]). All these enzymes use sucrose as their preferential donor substrate. Many of them can create very long levan-type fructans (catalyzed by levansucrases) or inulin-type of fructans (catalyzed by inulosucrases), as well as fructooligosacharides (FOS). However, some GH68 enzymes can also use fructan as donor substrate (in the abscence of sucrose or at a high fructan/sucrose ratio). <br />
<br />
== Kinetics and Mechanism ==<br />
Family GH68 enzymes as well as those included in [[GH32]] are [[retaining]] enzymes <cite>1</cite>. The levansucrases from ''Bacillus subtilis'', ''Gluconacetobacter diazotrophicus'', and ''Streptococcus salivarius'' catalyze transfructosylation via a ping-pong mechanism involving the formation of a transient fructosyl-enzyme intermediate <cite>2 3 4 5</cite>. At low sucrose concentrations levansucrase functions as a hydrolase with water as acceptor, whereas at higher substrate concentrations it adds fructosyl units to a variety of acceptors including glucose, fructan and sucrose <cite>2</cite>. Bacterial levansucrases, whatever their origin, catalyze all these reactions but with different efficiency.<br />
<br />
== Catalytic Residues ==<br />
GH68 [[retaining]] enzymes catalyze hydrolysis in two steps involving a covalent glycosyl enzyme [[intermediate]]. The two invariant residues, responsible for the catalytic reaction in family GH68 enzymes, have first been identified experimentally in bacterial levansucrases as an aspartate located close to the N-terminus acting as the [[catalytic nucleophile]] and a glutamate acting as the [[general acid/base]] <cite>6 7</cite>. In addition, a conserved aspartate residue in the "Arg-Asp-Pro (RDP) motif" stabilizes the [[transition state]] <cite>5 7 8</cite>. The three equivalent acidic residues have been mutated in a β-fructofuranosidase from ''Arthrobacter globiformis'' IFO 3062 <cite>9</cite>, and in a levansucrase and a inulosucrase from ''Lactobacillus reuteri'' 121 <cite>10</cite>.<br />
<br />
== Three-dimensional structures ==<br />
Currently, only three different three dimensional structures of family GH68 enzymes have been solved. The first crystal structure was reported for the bacterial levansucrase (SacB) from ''Bacillus subtilis'' subsp. subtilis str. 168 <cite>6</cite>. The second one corresponds to levansucrase (LdsA) from ''Gluconacetobacter diazotrophicus'' SRT4 <cite>11</cite>, and the last one corresponds to SacB from ''Bacillus megaterium'' <cite>15</cite>. These structures display a 5-fold β-propeller topology, and therefore GH families 68 and [[GH32|32]] have been combined in clan GH-J. On the other hand, a structural relationship of the catalytic core exists to family GH68 and family [[GH43]], as predicted by detailed sequence analysis<cite>12</cite>.<br />
<br />
== Family Firsts ==<br />
;First stereochemistry determination: ''Bacillus subtilis'' levansucrase <cite>2</cite>.<br />
;First [[catalytic nucleophile]] identification: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
;First [[general acid/base]] residue identification: ''Zymomonas mobilis'' levansucrase <cite>7</cite>.<br />
;First stabilizing [[transition state]] residue identification: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>11</cite>.<br />
;First prediction of a common beta-propeller catalytic domain in GH68 / clan GH-J: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>13 14</cite>.<br />
;First 3-D structure: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
<br />
== References ==<br />
<biblio><br />
#1 pmid=13174523<br />
#2 pmid=4206083<br />
#3 pmid=814002<br />
#4 pmid=7619044<br />
#5 pmid=10393084<br />
#6 pmid=14517548<br />
#7 pmid=12359071<br />
#8 pmid=9895294<br />
#9 pmid=16233623<br />
#10 pmid=14988011<br />
#11 pmid=15869470<br />
#12 pmid=11093261<br />
#13 pmid=9829697<br />
#14 pmid=11305239<br />
#15 pmid=21454585<br />
</biblio><br />
<br />
<br />
[[Category:Glycoside Hydrolase Families|GH068]]</div>Tirso Ponshttps://www.cazypedia.org/index.php?title=Glycoside_Hydrolase_Family_68&diff=6948Glycoside Hydrolase Family 682011-08-02T17:29:48Z<p>Tirso Pons: /* Three-dimensional structures */</p>
<hr />
<div><!-- CURATORS: Please replace the {{UnderConstruction}} tag below with {{CuratorApproved}} when the page is ready for wider public consumption --><br />
{{CuratorApproved}}<br />
* [[Author]]: ^^^Tirso Pons^^^ and ^^^Wim Van den Ende^^^<br />
* [[Responsible Curator]]: ^^^Wim Van den Ende^^^<br />
----<br />
<br />
<!-- The data in the table below should be updated by the Author/Curator according to current information on the family --><br />
<div style="float:right"><br />
{| {{Prettytable}} <br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH68'''<br />
|-<br />
|'''Clan''' <br />
|GH-J<br />
|-<br />
|'''Mechanism'''<br />
|retaining<br />
|-<br />
|'''Active site residues'''<br />
|known<br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br />
|-<br />
| colspan="2" |http://www.cazy.org/fam/GH68.html<br />
|}<br />
</div><br />
<!-- This is the end of the table --><br />
<br />
<br />
== Substrate specificities ==<br />
[[Glycoside hydrolase]] family 68 enzymes include levansucrase (sucrose:2,6-β-D-fructan 6-β-D-fructosyltransferase; EC [{{EClink}}2.4.1.10 2.4.1.10]), β-fructofuranosidase (EC [{{EClink}}3.2.1.26 3.2.1.26]), and inulosucrase (EC [{{EClink}}2.4.1.9 2.4.1.9]). All these enzymes use sucrose as their preferential donor substrate. Many of them can create very long levan-type fructans (catalyzed by levansucrases) or inulin-type of fructans (catalyzed by inulosucrases), as well as fructooligosacharides (FOS). However, some GH68 enzymes can also use fructan as donor substrate (in the abscence of sucrose or at a high fructan/sucrose ratio). <br />
<br />
== Kinetics and Mechanism ==<br />
Family GH68 enzymes as well as those included in [[GH32]] are [[retaining]] enzymes <cite>1</cite>. The levansucrases from ''Bacillus subtilis'', ''Gluconacetobacter diazotrophicus'', and ''Streptococcus salivarius'' catalyze transfructosylation via a ping-pong mechanism involving the formation of a transient fructosyl-enzyme intermediate <cite>2 3 4 5</cite>. At low sucrose concentrations levansucrase functions as a hydrolase with water as acceptor, whereas at higher substrate concentrations it adds fructosyl units to a variety of acceptors including glucose, fructan and sucrose <cite>2</cite>. Bacterial levansucrases, whatever their origin, catalyze all these reactions but with different efficiency.<br />
<br />
== Catalytic Residues ==<br />
GH68 [[retaining]] enzymes catalyze hydrolysis in two steps involving a covalent glycosyl enzyme [[intermediate]]. The two invariant residues, responsible for the catalytic reaction in family GH68 enzymes, have first been identified experimentally in bacterial levansucrases as an aspartate located close to the N-terminus acting as the [[catalytic nucleophile]] and a glutamate acting as the [[general acid/base]] <cite>6 7</cite>. In addition, a conserved aspartate residue in the "Arg-Asp-Pro (RDP) motif" stabilizes the [[transition state]] <cite>5 7 8</cite>. The three equivalent acidic residues have been mutated in a β-fructofuranosidase from ''Arthrobacter globiformis'' IFO 3062 <cite>9</cite>, and in a levansucrase and a inulosucrase from ''Lactobacillus reuteri'' 121 <cite>10</cite>.<br />
<br />
== Three-dimensional structures ==<br />
Currently, only three different three dimensional structures of family GH68 enzymes have been solved. The first crystal structure was reported for the bacterial levansucrase (SacB) from ''Bacillus subtilis'' subsp. subtilis str. 168 <cite>6</cite>. The second one corresponds to levansucrase (LdsA) from ''Gluconacetobacter diazotrophicus'' SRT4 <cite>11</cite>, and the last one corresponds to SacB from ''Bacillus megaterium'' <cite>15</cite>. These structures display a 5-fold β-propeller topology, and therefore GH families 68 and [[GH32|32]] have been combined in clan GH-J. On the other hand, a structural relationship of the catalytic core exists to family GH68 and family [[GH43]], as predicted by detailed sequence analysis<cite>12</cite>.<br />
<br />
== Family Firsts ==<br />
;First stereochemistry determination: ''Bacillus subtilis'' levansucrase <cite>2</cite>.<br />
;First [[catalytic nucleophile]] identification: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
;First [[general acid/base]] residue identification: ''Zymomonas mobilis'' levansucrase <cite>7</cite>.<br />
;First stabilizing [[transition state]] residue identification: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>8</cite>.<br />
;First prediction of a common beta-propeller catalytic domain in GH68 / clan GH-J: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>13 14</cite>.<br />
;First 3-D structure: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
<br />
== References ==<br />
<biblio><br />
#1 pmid=13174523<br />
#2 pmid=4206083<br />
#3 pmid=814002<br />
#4 pmid=7619044<br />
#5 pmid=10393084<br />
#6 pmid=14517548<br />
#7 pmid=12359071<br />
#8 pmid=9895294<br />
#9 pmid=16233623<br />
#10 pmid=14988011<br />
#11 pmid=15869470<br />
#12 pmid=11093261<br />
#13 pmid=9829697<br />
#14 pmid=11305239<br />
#15 pmid=2145458<br />
</biblio><br />
<br />
<br />
[[Category:Glycoside Hydrolase Families|GH068]]</div>Tirso Ponshttps://www.cazypedia.org/index.php?title=Glycoside_Hydrolase_Family_68&diff=6947Glycoside Hydrolase Family 682011-08-02T17:28:08Z<p>Tirso Pons: </p>
<hr />
<div><!-- CURATORS: Please replace the {{UnderConstruction}} tag below with {{CuratorApproved}} when the page is ready for wider public consumption --><br />
{{CuratorApproved}}<br />
* [[Author]]: ^^^Tirso Pons^^^ and ^^^Wim Van den Ende^^^<br />
* [[Responsible Curator]]: ^^^Wim Van den Ende^^^<br />
----<br />
<br />
<!-- The data in the table below should be updated by the Author/Curator according to current information on the family --><br />
<div style="float:right"><br />
{| {{Prettytable}} <br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH68'''<br />
|-<br />
|'''Clan''' <br />
|GH-J<br />
|-<br />
|'''Mechanism'''<br />
|retaining<br />
|-<br />
|'''Active site residues'''<br />
|known<br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br />
|-<br />
| colspan="2" |http://www.cazy.org/fam/GH68.html<br />
|}<br />
</div><br />
<!-- This is the end of the table --><br />
<br />
<br />
== Substrate specificities ==<br />
[[Glycoside hydrolase]] family 68 enzymes include levansucrase (sucrose:2,6-β-D-fructan 6-β-D-fructosyltransferase; EC [{{EClink}}2.4.1.10 2.4.1.10]), β-fructofuranosidase (EC [{{EClink}}3.2.1.26 3.2.1.26]), and inulosucrase (EC [{{EClink}}2.4.1.9 2.4.1.9]). All these enzymes use sucrose as their preferential donor substrate. Many of them can create very long levan-type fructans (catalyzed by levansucrases) or inulin-type of fructans (catalyzed by inulosucrases), as well as fructooligosacharides (FOS). However, some GH68 enzymes can also use fructan as donor substrate (in the abscence of sucrose or at a high fructan/sucrose ratio). <br />
<br />
== Kinetics and Mechanism ==<br />
Family GH68 enzymes as well as those included in [[GH32]] are [[retaining]] enzymes <cite>1</cite>. The levansucrases from ''Bacillus subtilis'', ''Gluconacetobacter diazotrophicus'', and ''Streptococcus salivarius'' catalyze transfructosylation via a ping-pong mechanism involving the formation of a transient fructosyl-enzyme intermediate <cite>2 3 4 5</cite>. At low sucrose concentrations levansucrase functions as a hydrolase with water as acceptor, whereas at higher substrate concentrations it adds fructosyl units to a variety of acceptors including glucose, fructan and sucrose <cite>2</cite>. Bacterial levansucrases, whatever their origin, catalyze all these reactions but with different efficiency.<br />
<br />
== Catalytic Residues ==<br />
GH68 [[retaining]] enzymes catalyze hydrolysis in two steps involving a covalent glycosyl enzyme [[intermediate]]. The two invariant residues, responsible for the catalytic reaction in family GH68 enzymes, have first been identified experimentally in bacterial levansucrases as an aspartate located close to the N-terminus acting as the [[catalytic nucleophile]] and a glutamate acting as the [[general acid/base]] <cite>6 7</cite>. In addition, a conserved aspartate residue in the "Arg-Asp-Pro (RDP) motif" stabilizes the [[transition state]] <cite>5 7 8</cite>. The three equivalent acidic residues have been mutated in a β-fructofuranosidase from ''Arthrobacter globiformis'' IFO 3062 <cite>9</cite>, and in a levansucrase and a inulosucrase from ''Lactobacillus reuteri'' 121 <cite>10</cite>.<br />
<br />
== Three-dimensional structures ==<br />
Currently, only three different three dimensional structures of family GH68 enzymes have been solved. The first crystal structure was reported for the bacterial levansucrase (SacB) from ''Bacillus subtilis'' subsp. subtilis str. 168 <cite>6</cite>. The second one corresponds to levansucrase (LdsA) from ''Gluconacetobacter diazotrophicus'' SRT4 <cite>11</cite>, and the last one corresponds to SacB from ''Bacillus megaterium'' <cite>15</cite>. These structures display a 5-fold β-propeller topology, and therefore GH families 68 and [[GH32|32]] have been combined in clan GH-J. On the other hand, a structural relationship of the catalytic core exists to family GH68 and family [[GH43]], as predicted by detailed sequence analysis<cite>12</cite>. <br />
<br />
== Family Firsts ==<br />
;First stereochemistry determination: ''Bacillus subtilis'' levansucrase <cite>2</cite>.<br />
;First [[catalytic nucleophile]] identification: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
;First [[general acid/base]] residue identification: ''Zymomonas mobilis'' levansucrase <cite>7</cite>.<br />
;First stabilizing [[transition state]] residue identification: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>8</cite>.<br />
;First prediction of a common beta-propeller catalytic domain in GH68 / clan GH-J: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>13 14</cite>.<br />
;First 3-D structure: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
<br />
== References ==<br />
<biblio><br />
#1 pmid=13174523<br />
#2 pmid=4206083<br />
#3 pmid=814002<br />
#4 pmid=7619044<br />
#5 pmid=10393084<br />
#6 pmid=14517548<br />
#7 pmid=12359071<br />
#8 pmid=9895294<br />
#9 pmid=16233623<br />
#10 pmid=14988011<br />
#11 pmid=15869470<br />
#12 pmid=11093261<br />
#13 pmid=9829697<br />
#14 pmid=11305239<br />
#15 pmid=2145458<br />
</biblio><br />
<br />
<br />
[[Category:Glycoside Hydrolase Families|GH068]]</div>Tirso Ponshttps://www.cazypedia.org/index.php?title=User:Tirso_Pons&diff=6946User:Tirso Pons2011-07-31T12:50:51Z<p>Tirso Pons: </p>
<hr />
<div>[[File:Tirso-03.jpg|200px|right]]<br />
'''Tirso Pons''' obtained his B.Sc. degree in Nuclear Physics from the Institute of Nuclear Sciences, Havana, then completed his Ph.D. in Biology at University of Havana with Joaquin Diaz and Alfonso Valencia in 2002, working on the sequence analysis, and structure and functional residues prediction for glycoside hydrolase [[GH32]], [[GH49]] and [[GH68]] families. He and colleagues predicted for the first time a common beta-propeller fold for the catalytic domain in [[GH32]] and [[GH68]] families, and also proposed the aspartate residue in the conserved "Arg-Asp-Pro (RDP) motif" as a third residue important for catalysis. Through collaboration with Prof. ^^^Gideon Davies^^^ (York University, UK), he and colleagues determined the crystal structure of levansucrase from the gram-negative bacterium ''Gluconacetobacter diazotrophicus'' SRT4. Tirso was a visiting scientist at Dr. Alfonso Valencia's Lab (CNB-CSIC) at the Autonomous University of Madrid, Spain, and at Dr. Gert Vriend's lab at the European Molecular Biology Laboratory (EMBL), Heidelberg, Germany.<br />
In 2007 and 2010 he obtained postdoctoral SEBiot and EMBO fellowships at the Structural Biology and Biocomputing Programme of the Spanish National Cancer Research Centre (CNIO), Madrid. From 2006 to 2011, he was an Associate Professor at Deparment of Biochemistry, and permanent researcher at the Center for Protein Research (CEP), Faculty of Biology, University of Havana. He is currently a staff scientists in the Structural Computational Biology Group within the Structural Biology and Biocomputing Programme at CNIO.<br />
More details are available at the web sites [http://www.researcherid.com/rid/A-6377-2011] or [http://www.iamscientist.com/people/tpons]<br />
[[Category:Contributors|Pons,Tirso]]</div>Tirso Ponshttps://www.cazypedia.org/index.php?title=User:Tirso_Pons&diff=6945User:Tirso Pons2011-07-31T12:42:58Z<p>Tirso Pons: </p>
<hr />
<div>[[File:Tirso-03.jpg|200px|right]]<br />
'''Tirso Pons''' obtained his B.Sc. degree in Nuclear Physics from the Institute of Nuclear Sciences, Havana, then completed his Ph.D. in Biology at University of Havana with Joaquin Diaz and Alfonso Valencia in 2002, working on the sequence analysis, and structure and functional residues prediction for glycoside hydrolase [[GH32]], [[GH49]] and [[GH68]] families. He and colleagues predicted for the first time a common beta-propeller fold for the catalytic domain in [[GH32]] and [[GH68]] families, and also proposed the aspartate residue in the conserved "Arg-Asp-Pro (RDP) motif" as a third residue important for catalysis. Through collaboration with Prof. ^^^Gideon Davies^^^ (York University, UK), he and colleagues determined the crystal structure of levansucrase from the gram-negative bacterium ''Gluconacetobacter diazotrophicus'' SRT4. Tirso was a visiting scientist at Dr. Alfonso Valencia's Lab (CNB-CSIC) at the Autonomous University of Madrid, Spain, and at Dr. Gert Vriend's lab at the European Molecular Biology Laboratory (EMBL), Heidelberg, Germany.<br />
In 2007 and 2010 he obtained postdoctoral SEBiot and EMBO fellowships at the Structural Biology and Biocomputing Programme of the Spanish National Cancer Research Centre (CNIO), Madrid. From 2006 to 2011, he was an Associate Professor at Deparment of Biochemistry, and permanent researcher at the Center for Protein Research (CEP), Faculty of Biology, University of Havana. He is currently a staff scientists in the Structural Computational Biology Group within the Structural Biology and Biocomputing Programme at CNIO.<br />
<br />
<br />
[[Category:Contributors|Pons,Tirso]]</div>Tirso Ponshttps://www.cazypedia.org/index.php?title=User:Tirso_Pons&diff=6944User:Tirso Pons2011-07-31T12:41:53Z<p>Tirso Pons: </p>
<hr />
<div>[[File:Tirso-03.jpg|200px|right]]<br />
'''Tirso Pons''' obtained his B.Sc. degree in Nuclear Physics from the Institute of Nuclear Sciences, Havana, then completed his Ph.D. in Biology at University of Havana with Joaquin Diaz and Alfonso Valencia in 2002, working on the sequence analysis, and structure and functional residues prediction for glycoside hydrolase [[GH32]], [[GH49]] and [[GH68]] families. He and colleagues predicted for the first time a common beta-propeller fold for the catalytic domain in [[GH32]] and [[GH68]] families, and also proposed the aspartate residue in the conserved "Arg-Asp-Pro (RDP) motif" as a third residue important for catalysis. Through collaboration with Prof. ^^^Gideon Davies^^^ (York University, UK), he and colleagues determined the crystal structure of levansucrase from the gram-negative bacterium ''Gluconacetobacter diazotrophicus'' SRT4. Tirso was a visiting scientist at Dr. Alfonso Valencia's Lab (CNB-CSIC) at the Autonomous University of Madrid, Spain, and at Dr. Gert Vriend's lab at the European Molecular Biology Laboratory (EMBL), Heidelberg, Germany.<br />
In 2007 and 2010 he obtained postdoctoral SEBiot and EMBO fellowships at the Structural Biology and Biocomputing Programme of the Spanish National Cancer Research Centre (CNIO), Madrid. Normal 0 21 false false false MicrosoftInternetExplorer4 From 2006 to 2011, he was an Associate Professor at Deparment of Biochemistry, and permanent researcher at the Center for Protein Research (CEP), Faculty of Biology, University of Havana. He is currently a staff scientists in the Structural Computational Biology Group within the Structural Biology and Biocomputing Programme at CNIO.<br />
<br />
<br />
[[Category:Contributors|Pons,Tirso]]</div>Tirso Ponshttps://www.cazypedia.org/index.php?title=Glycoside_Hydrolase_Family_68&diff=4002Glycoside Hydrolase Family 682010-02-18T17:18:35Z<p>Tirso Pons: </p>
<hr />
<div><!-- CURATORS: Please replace the {{UnderConstruction}} tag below with {{CuratorApproved}} when the page is ready for wider public consumption --><br />
{{UnderConstruction}}<br />
* [[Author]]: ^^^Tirso Pons^^^ and ^^^Wim Van den Ende^^^<br />
* [[Responsible Curator]]: ^^^Wim Van den Ende^^^<br />
----<br />
<br />
<!-- The data in the table below should be updated by the Author/Curator according to current information on the family --><br />
<div style="float:right"><br />
{| {{Prettytable}} <br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH68'''<br />
|-<br />
|'''Clan''' <br />
|GH-J<br />
|-<br />
|'''Mechanism'''<br />
|retaining<br />
|-<br />
|'''Active site residues'''<br />
|known<br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br />
|-<br />
| colspan="2" |http://www.cazy.org/fam/GH68.html<br />
|}<br />
</div><br />
<!-- This is the end of the table --><br />
<br />
<br />
== Substrate specificities ==<br />
Glycoside hydrolase family GH68 enzymes include levansucrase (sucrose:2,6-β-D-fructan 6-β-D-fructosyltransferase; EC 2.4.1.10), β-fructofuranosidase (EC 3.2.1.26), and inulosucrase (EC 2.4.1.9). All these enzymes use sucrose as their preferential donor substrate. Many of them can create very long levan-type fructans (catalyzed by levansucrases) or inulin-type of fructans (catalyzed by inulosucrases), as well as fructooligosacharides (FOS). However, some GH68 enzymes can also use fructan as donor substrate (in the abscence of sucrose or at a high fructan/sucrose ratio). <br />
<br />
== Kinetics and Mechanism ==<br />
Family GH68 enzymes as well as those included in [[GH32]] are retaining enzymes <cite>1</cite>. The levansucrases from ''Bacillus subtilis'', ''Gluconacetobacter diazotrophicus'', and ''Streptococcus salivarius'' catalyze transfructosylation via a Ping-Pong mechanism involving the formation of a transient fructosyl-enzyme intermediate <cite>2 3 4 5</cite>. At low sucrose concentrations levansucrase functions as a hydrolase with water as acceptor, whereas at higher substrate concentrations it adds fructosyl units to a variety of acceptors including glucose, fructan and sucrose <cite>2</cite>. Bacterial levansucrases, whatever their origin, catalyze all these reactions but with different efficiency.<br />
<br />
== Catalytic Residues ==<br />
Retaining glycosidases catalyze hydrolysis in two steps involving a covalent glycosyl enzyme intermediate. The two invariant residues, responsible for the catalytic reaction in family GH68 enzymes, have first been identified experimentally in bacterial levansucrases as an aspartate located close to the N-terminus acting as the catalytic nucleophile and a glutamate acting as the general acid/base <cite>6 7</cite>. In addition, a conserved aspartate residue in the "Arg-Asp-Pro (RDP) motif" stabilizes the transition state <cite>5 7 8</cite>. The three equivalent acidic residues have been mutated in a β-fructofuranosidase from ''Arthrobacter globiformis'' IFO 3062 <cite>9</cite>, and in a levansucrase and a inulosucrase from ''Lactobacillus reuteri'' 121 <cite>10</cite>.<br />
<br />
== Three-dimensional structures ==<br />
Currently, only two different three dimensional structures of family GH68 enzymes have been solved. The first crystal structure was reported for the bacterial levansucrase (SacB) from ''Bacillus subtilis'' subsp. subtilis str. 168 <cite>6</cite>. The second one corresponds to levansucrase (LdsA) from ''Gluconacetobacter diazotrophicus'' SRT4 <cite>11</cite>. These structures display a 5-fold β-propeller topology, and therefore GH families 68 and 32 are combined in clan GH-J. On the other hand, a structural relationship of the catalytic core exists to family GH68 and family [[GH43]], as predicted by detailed sequence analysis<cite>12</cite>. <br />
<br />
<br />
== Family Firsts ==<br />
;First stereochemistry determination: ''Bacillus subtilis'' levansucrase <cite>2</cite>.<br />
;First catalytic nucleophile identification: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
;First general acid/base residue identification: ''Zymomonas mobilis'' levansucrase <cite>7</cite>.<br />
;First stabilizing transition-state residue identification: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>8</cite>.<br />
;First prediction of a common beta-propeller catalytic domain in GH68 / clan GH-J: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>13 14</cite>.<br />
;First 3-D structure: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
<br />
== References ==<br />
<biblio><br />
#1 pmid=13174523<br />
#2 pmid=4206083<br />
#3 pmid=814002<br />
#4 pmid=7619044<br />
#5 pmid=10393084<br />
#6 pmid=14517548<br />
#7 pmid=12359071<br />
#8 pmid=9895294<br />
#9 pmid=16233623<br />
#10 pmid=14988011<br />
#11 pmid=15869470<br />
#12 pmid=11093261<br />
#13 pmid=9829697<br />
#14 pmid=11305239<br />
</biblio><br />
<br />
<br />
[[Category:Glycoside Hydrolase Families|GH068]]</div>Tirso Ponshttps://www.cazypedia.org/index.php?title=Glycoside_Hydrolase_Family_68&diff=4001Glycoside Hydrolase Family 682010-02-18T17:15:41Z<p>Tirso Pons: </p>
<hr />
<div><!-- CURATORS: Please replace the {{UnderConstruction}} tag below with {{CuratorApproved}} when the page is ready for wider public consumption --><br />
{{UnderConstruction}}<br />
* [[Author]]: ^^^Tirso Pons^^^ and ^^^Wim Van den Ende^^^<br />
* [[Responsible Curator]]: ^^^Wim Van den Ende^^^<br />
----<br />
<br />
<!-- The data in the table below should be updated by the Author/Curator according to current information on the family --><br />
<div style="float:right"><br />
{| {{Prettytable}} <br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH68'''<br />
|-<br />
|'''Clan''' <br />
|GH-J<br />
|-<br />
|'''Mechanism'''<br />
|retaining<br />
|-<br />
|'''Active site residues'''<br />
|known<br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br />
|-<br />
| colspan="2" |http://www.cazy.org/fam/GH68.html<br />
|}<br />
</div><br />
<!-- This is the end of the table --><br />
<br />
<br />
== Substrate specificities ==<br />
Glycoside hydrolase family GH68 enzymes include levansucrase (sucrose:2,6-β-D-fructan 6-β-D-fructosyltransferase; EC 2.4.1.10), β-fructofuranosidase (EC 3.2.1.26), and inulosucrase (EC 2.4.1.9). All these enzymes use sucrose as their preferential donor substrate. Many of them can create very long levan-type fructans (catalyzed by levansucrases) or inulin-type of fructans (catalyzed by inulosucrases), as well as fructooligosacharides (FOS). However, some GH68 enzymes can also use fructan as donor substrate (in the abscence of sucrose or at a high fructan/sucrose ratio). <br />
<br />
== Kinetics and Mechanism ==<br />
Family GH68 enzymes as well as those included in [[GH32]] are retaining enzymes <cite>1</cite>. The levansucrases from ''Bacillus subtilis'', ''Gluconacetobacter diazotrophicus'', and ''Streptococcus salivarius'' catalyze transfructosylation via a Ping-Pong mechanism involving the formation of a transient fructosyl-enzyme intermediate <cite>2 3 4 5</cite>. At low sucrose concentrations levansucrase functions as a hydrolase with water as acceptor, whereas at higher substrate concentrations it adds fructosyl units to a variety of acceptors including glucose, fructan and sucrose <cite>2</cite>. Bacterial levansucrases, whatever their origin, catalyze all these reactions but with different efficiency.<br />
<br />
== Catalytic Residues ==<br />
Retaining glycosidases catalyze hydrolysis in two steps involving a covalent glycosyl enzyme intermediate. The two invariant residues, responsible for the catalytic reaction in family GH68 enzymes, have first been identified experimentally in bacterial levansucrases as an aspartate located close to the N-terminus acting as the catalytic nucleophile and a glutamate acting as the general acid/base <cite>6 7</cite>. In addition, a conserved aspartate residue in the "Arg-Asp-Pro (RDP) motif" stabilizes the transition state <cite>5 7 8</cite>. The three equivalent acidic residues have been mutated in a β-fructofuranosidase from ''Arthrobacter globiformis'' IFO 3062 <cite>9</cite>, and in a levansucrase and a inulosucrase from ''Lactobacillus reuteri'' 121 <cite>10</cite>.<br />
<br />
== Three-dimensional structures ==<br />
Currently, only two different three dimensional structures of family GH68 enzymes have been solved. The first crystal structure was reported for the bacterial levansucrase (SacB) from ''Bacillus subtilis'' subsp. subtilis str. 168 <cite>6</cite>. The second one corresponds to levansucrase (LdsA) from ''Gluconacetobacter diazotrophicus'' SRT4 <cite>11</cite>. These structures display a 5-fold β-propeller topology, and therefore GH families 68 and 32 are combined in clan [[GH-J]]. On the other hand, a structural relationship of the catalytic core exists to family GH68 and family [[GH43]], as predicted by detailed sequence analysis<cite>12</cite>. <br />
<br />
<br />
== Family Firsts ==<br />
;First stereochemistry determination: ''Bacillus subtilis'' levansucrase <cite>2</cite>.<br />
;First catalytic nucleophile identification: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
;First general acid/base residue identification: ''Zymomonas mobilis'' levansucrase <cite>7</cite>.<br />
;First stabilizing transition-state residue identification: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>8</cite>.<br />
;First prediction of a common beta-propeller catalytic domain in GH68 / clan GH-J: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>13 14</cite>.<br />
;First 3-D structure: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
<br />
== References ==<br />
<biblio><br />
#1 pmid=13174523<br />
#2 pmid=4206083<br />
#3 pmid=814002<br />
#4 pmid=7619044<br />
#5 pmid=10393084<br />
#6 pmid=14517548<br />
#7 pmid=12359071<br />
#8 pmid=9895294<br />
#9 pmid=16233623<br />
#10 pmid=14988011<br />
#11 pmid=15869470<br />
#12 pmid=11093261<br />
#13 pmid=9829697<br />
#14 pmid=11305239<br />
</biblio><br />
<br />
<br />
[[Category:Glycoside Hydrolase Families|GH068]]</div>Tirso Ponshttps://www.cazypedia.org/index.php?title=User:Tirso_Pons&diff=4000User:Tirso Pons2010-02-18T17:11:05Z<p>Tirso Pons: </p>
<hr />
<div>[[File:Tirso-03.jpg|200px|thumb|right|alt text]]<br />
'''Tirso Pons''' obtained his B.Sc. degree in Nuclear Physics from the Institute of Nuclear Sciences, Havana, then completed his Ph.D. in Biology at University of Havana with Joaquin Diaz and Alfonso Valencia in 2002, working on the sequence analysis, and structure and functional residues prediction for glycosyde hydrolase [[GH32]], [[GH49]] and [[GH68]] families. He and colleagues predicted for the first time a common beta-propeller fold for the catalytic domain in [[GH32]] and [[GH68]] families, and also proposed the aspartate residue in the conserved "Arg-Asp-Pro (RDP) motif" as a third residue important for catalysis. Through collaboration with Prof. ^^^Gideon Davies^^^ (York University, UK), he and colleagues determined the crystal structure of levansucrase from the gram-negative bacterium ''Gluconacetobacter diazotrophicus'' SRT4. Tirso was a visiting scientist at Dr. Alfonso Valencia's Lab (CNB-CSIC) at the Autonomous University of Madrid, Spain, and at Dr. Gert Vriend's lab at the European Molecular Biology Laboratory (EMBL), Heidelberg, Germany.<br />
In 2007 and 2010 he obtained postdoctoral SEBiot and EMBO fellowships at the Structural Biology and Biocomputing Programme of the Spanish National Cancer Research Centre (CNIO), Madrid. He is currently an Associate Professor at Deparment of Biochemistry, and permanent researcher at the Center for Protein Research (CEP), Faculty of Biology, University of Havana.<br />
<br />
<br />
[[Category:Contributors|Pons,Tirso]]</div>Tirso Ponshttps://www.cazypedia.org/index.php?title=User:Tirso_Pons&diff=3999User:Tirso Pons2010-02-18T17:06:35Z<p>Tirso Pons: </p>
<hr />
<div>[[File:Tirso-03.jpg|200px|thumb|right|alt text]]<br />
'''Tirso Pons''' obtained his B.Sc. degree in Nuclear Physics from the Institute of Nuclear Sciences, Havana, then completed his Ph.D. in Biology at University of Havana with Joaquin Diaz and Alfonso Valencia in 2002, working on the sequence analysis, and structure and functional residues prediction for glycosyde hydrolase [[GH32]], [[GH49]] and [[GH68]] families. He and colleagues predicted for the first time a common beta-propeller fold for the catalytic domain in [[GH32]] and [[GH68]] families, and also proposed the aspartate residue in the conserved "Arg-Asp-Pro (RDP) motif" as a third residue important for catalysis. Through collaboration with Prof. ^^^Gideon Davies^^^ (York University, UK), he and colleagues determined the crystal structure of levansucrase from the gram-negative bacterium ''Gluconacetobacter diazotrophicus''. Tirso was a visiting scientist at Dr. Alfonso Valencia's Lab (CNB-CSIC) at the Autonomous University of Madrid, Spain, and at Dr. Gert Vriend's lab at the European Molecular Biology Laboratory (EMBL), Heidelberg, Germany.<br />
In 2007 and 2010 he obtained postdoctoral SEBiot and EMBO fellowships at the Structural Biology and Biocomputing Programme of the Spanish National Cancer Research Centre (CNIO), Madrid. He is currently an Associate Professor at Deparment of Biochemistry, and permanent researcher at the Center for Protein Research (CEP), Faculty of Biology, University of Havana.<br />
<br />
<br />
[[Category:Contributors|Pons,Tirso]]</div>Tirso Ponshttps://www.cazypedia.org/index.php?title=File:Tirso-03.jpg&diff=3992File:Tirso-03.jpg2010-02-18T15:16:49Z<p>Tirso Pons: </p>
<hr />
<div></div>Tirso Ponshttps://www.cazypedia.org/index.php?title=Glycoside_Hydrolase_Family_68&diff=3991Glycoside Hydrolase Family 682010-02-18T12:59:13Z<p>Tirso Pons: </p>
<hr />
<div><!-- CURATORS: Please replace the {{UnderConstruction}} tag below with {{CuratorApproved}} when the page is ready for wider public consumption --><br />
{{UnderConstruction}}<br />
* [[Author]]: ^^^Tirso Pons^^^ and ^^^Wim Van den Ende^^^<br />
* [[Responsible Curator]]: ^^^Wim Van den Ende^^^<br />
----<br />
<br />
<!-- The data in the table below should be updated by the Author/Curator according to current information on the family --><br />
<div style="float:right"><br />
{| {{Prettytable}} <br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH68'''<br />
|-<br />
|'''Clan''' <br />
|GH-J<br />
|-<br />
|'''Mechanism'''<br />
|retaining<br />
|-<br />
|'''Active site residues'''<br />
|known<br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br />
|-<br />
| colspan="2" |http://www.cazy.org/fam/GH68.html<br />
|}<br />
</div><br />
<!-- This is the end of the table --><br />
<br />
<br />
== Substrate specificities ==<br />
Glycoside hydrolase family GH68 enzymes include levansucrase (sucrose:2,6-β-D-fructan 6-β-D-fructosyltransferase; EC 2.4.1.10), β-fructofuranosidase (EC 3.2.1.26), and inulosucrase (EC 2.4.1.9). All these enzymes use sucrose as their preferential donor substrate. Many of them can create very long levan-type fructans (catalyzed by levansucrases) or inulin-type of fructans (catalyzed by inulosucrases), as well as fructooligosacharides (FOS). However, some GH68 enzymes can also use fructan as donor substrate (in the abscence of sucrose or at a high fructan/sucrose ratio). <br />
<br />
== Kinetics and Mechanism ==<br />
Family GH68 enzymes as well as those included in GH32 are retaining enzymes <cite>1</cite>. The levansucrases from ''Bacillus subtilis'', ''Gluconacetobacter diazotrophicus'', and ''Streptococcus salivarius'' catalyze transfructosylation via a Ping-Pong mechanism involving the formation of a transient fructosyl-enzyme intermediate <cite>2 3 4 5</cite>. At low sucrose concentrations levansucrase functions as a hydrolase with water as acceptor, whereas at higher substrate concentrations it adds fructosyl units to a variety of acceptors including glucose, fructan and sucrose <cite>2</cite>. Bacterial levansucrases, whatever their origin, catalyze all these reactions but with different efficiency.<br />
<br />
== Catalytic Residues ==<br />
Retaining glycosidases catalyze hydrolysis in two steps involving a covalent glycosyl enzyme intermediate. The two invariant residues, responsible for the catalytic reaction in family GH68 enzymes, have first been identified experimentally in bacterial levansucrases as an aspartate located close to the N-terminus acting as the catalytic nucleophile and a glutamate acting as the general acid/base <cite>6 7</cite>. In addition, a conserved aspartate residue in the "Arg-Asp-Pro (RDP) motif" stabilizes the transition state <cite>5 7 8</cite>. The three equivalent acidic residues have been mutated in a β-fructofuranosidase from ''Arthrobacter globiformis'' IFO 3062 <cite>9</cite>, and in a levansucrase and a inulosucrase from ''Lactobacillus reuteri'' 121 <cite>10</cite>.<br />
<br />
== Three-dimensional structures ==<br />
Currently, only two different three dimensional structures of family GH68 enzymes have been solved. The first crystal structure was reported for the bacterial levansucrase (SacB) from ''Bacillus subtilis'' subsp. subtilis str. 168 <cite>6</cite>. The second one corresponds to levansucrase (LdsA) from ''Gluconacetobacter diazotrophicus'' SRT4 <cite>11</cite>. These structures display a 5-fold β-propeller topology, and therefore GH families 68 and 32 are combined in clan GH-J. On the other hand, a structural relationship of the catalytic core exists to family GH68 and family GH43, as predicted by detailed sequence analysis<cite>12</cite>. <br />
<br />
<br />
== Family Firsts ==<br />
;First stereochemistry determination: ''Bacillus subtilis'' levansucrase <cite>2</cite>.<br />
;First catalytic nucleophile identification: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
;First general acid/base residue identification: ''Zymomonas mobilis'' levansucrase <cite>7</cite>.<br />
;First stabilizing transition-state residue identification: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>8</cite>.<br />
;First prediction of a common beta-propeller catalytic domain in GH68 / clan GH-J: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>13 14</cite>.<br />
;First 3-D structure: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
<br />
== References ==<br />
<biblio><br />
#1 pmid=13174523<br />
#2 pmid=4206083<br />
#3 pmid=814002<br />
#4 pmid=7619044<br />
#5 pmid=10393084<br />
#6 pmid=14517548<br />
#7 pmid=12359071<br />
#8 pmid=9895294<br />
#9 pmid=16233623<br />
#10 pmid=14988011<br />
#11 pmid=15869470<br />
#12 pmid=11093261<br />
#13 pmid=9829697<br />
#14 pmid=11305239<br />
</biblio><br />
<br />
<br />
[[Category:Glycoside Hydrolase Families|GH068]]</div>Tirso Ponshttps://www.cazypedia.org/index.php?title=Glycoside_Hydrolase_Family_68&diff=3990Glycoside Hydrolase Family 682010-02-18T10:58:51Z<p>Tirso Pons: </p>
<hr />
<div><!-- CURATORS: Please replace the {{UnderConstruction}} tag below with {{CuratorApproved}} when the page is ready for wider public consumption --><br />
{{UnderConstruction}}<br />
* [[Author]]: ^^^Tirso Pons^^^ and ^^^Wim Van den Ende^^^<br />
* [[Responsible Curator]]: ^^^Wim Van den Ende^^^<br />
----<br />
<br />
<!-- The data in the table below should be updated by the Author/Curator according to current information on the family --><br />
<div style="float:right"><br />
{| {{Prettytable}} <br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH68'''<br />
|-<br />
|'''Clan''' <br />
|GH-J<br />
|-<br />
|'''Mechanism'''<br />
|retaining<br />
|-<br />
|'''Active site residues'''<br />
|known<br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br />
|-<br />
| colspan="2" |http://www.cazy.org/fam/GH68.html<br />
|}<br />
</div><br />
<!-- This is the end of the table --><br />
<br />
<br />
== Substrate specificities ==<br />
Glycoside hydrolase family GH68 contains enzymes that use sucrose as their preferential donor substrate and many of them can create very long levan or inulin-type of fructans, as well as fructooligosacharides (FOS). However, some levansucrase or inulinase enzymes can also use fructan as donor substrate in the abscence of sucrose or at a high fructan/sucrose ratio. Family GH68 includes levansucrase (sucrose:2,6-β-D-fructan 6-β-D-fructosyltransferase; EC 2.4.1.10), β-fructofuranosidase (EC 3.2.1.26), and inulosucrase (EC 2.4.1.9).<br />
<br />
== Kinetics and Mechanism ==<br />
Family GH68 enzymes as well as those included in GH32 are retaining enzymes <cite>1</cite>. The levansucrases from ''Bacillus subtilis'', ''Gluconacetobacter diazotrophicus'', and ''Streptococcus salivarius'' catalyze transfructosylation via a Ping-Pong mechanism involving the formation of a transient fructosyl-enzyme intermediate <cite>2 3 4 5</cite>. At low sucrose concentrations levansucrase functions as a hydrolase with water as acceptor, whereas at higher substrate concentrations it adds fructosyl units to a variety of acceptors including glucose, fructan and sucrose <cite>2</cite>. Bacterial levansucrases, whatever their origin, catalyze all these reactions but with different efficiency.<br />
<br />
== Catalytic Residues ==<br />
Retaining glycosidases catalyze hydrolysis in two steps involving a covalent glycosyl enzyme intermediate. The two invariant residues, responsible for the catalytic reaction in family GH68 enzymes, have first been identified experimentally in bacterial levansucrases as an aspartate located close to the N-terminus acting as the catalytic nucleophile and a glutamate acting as the general acid/base <cite>6 7</cite>. In addition, a conserved aspartate residue in the "Arg-Asp-Pro (RDP) motif" stabilizes the transition state <cite>5 7 8</cite>. The three equivalent acidic residues have been mutated in a β-fructofuranosidase from ''Arthrobacter globiformis'' IFO 3062 <cite>9</cite>, and in a levansucrase and a inulosucrase from ''Lactobacillus reuteri'' 121 <cite>10</cite>.<br />
<br />
== Three-dimensional structures ==<br />
Currently, only two different three dimensional structures of family GH68 enzymes have been solved. The first crystal structure was reported for the bacterial levansucrase (SacB) from ''Bacillus subtilis'' subsp. subtilis str. 168 <cite>6</cite>. The second one corresponds to levansucrase (LdsA) from ''Gluconacetobacter diazotrophicus'' SRT4 <cite>11</cite>. These structures display a 5-fold β-propeller topology, and therefore GH families 68 and 32 are combined in clan GH-J. On the other hand, a structural relationship of the catalytic core exists to family GH68 and family GH43, as predicted by detailed sequence analysis<cite>12</cite>. <br />
<br />
<br />
== Family Firsts ==<br />
;First stereochemistry determination: ''Bacillus subtilis'' levansucrase <cite>2</cite>.<br />
;First catalytic nucleophile identification: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
;First general acid/base residue identification: ''Zymomonas mobilis'' levansucrase <cite>7</cite>.<br />
;First stabilizing transition-state residue identification: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>8</cite>.<br />
;First prediction of a common beta-propeller catalytic domain in GH68 / clan GH-J: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>13 14</cite>.<br />
;First 3-D structure: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
<br />
== References ==<br />
<biblio><br />
#1 pmid=13174523<br />
#2 pmid=4206083<br />
#3 pmid=814002<br />
#4 pmid=7619044<br />
#5 pmid=10393084<br />
#6 pmid=14517548<br />
#7 pmid=12359071<br />
#8 pmid=9895294<br />
#9 pmid=16233623<br />
#10 pmid=14988011<br />
#11 pmid=15869470<br />
#12 pmid=11093261<br />
#13 pmid=9829697<br />
#14 pmid=11305239<br />
</biblio><br />
<br />
<br />
[[Category:Glycoside Hydrolase Families|GH068]]</div>Tirso Ponshttps://www.cazypedia.org/index.php?title=Glycoside_Hydrolase_Family_68&diff=3989Glycoside Hydrolase Family 682010-02-18T10:57:32Z<p>Tirso Pons: </p>
<hr />
<div><!-- CURATORS: Please replace the {{UnderConstruction}} tag below with {{CuratorApproved}} when the page is ready for wider public consumption --><br />
{{UnderConstruction}}<br />
* [[Author]]: ^^^Tirso Pons^^^ and ^^^Wim Van den Ende^^^<br />
* [[Responsible Curator]]: ^^^Wim Van den Ende^^^<br />
----<br />
<br />
<!-- The data in the table below should be updated by the Author/Curator according to current information on the family --><br />
<div style="float:right"><br />
{| {{Prettytable}} <br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH68'''<br />
|-<br />
|'''Clan''' <br />
|GH-J<br />
|-<br />
|'''Mechanism'''<br />
|retaining<br />
|-<br />
|'''Active site residues'''<br />
|known<br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br />
|-<br />
| colspan="2" |http://www.cazy.org/fam/GH68.html<br />
|}<br />
</div><br />
<!-- This is the end of the table --><br />
<br />
<br />
== Substrate specificities ==<br />
Glycoside hydrolase family GH68 contains enzymes that use sucrose as their preferential donor substrate and many of them can create very long levan or inulin-type of fructans, as well as fructooligosacharides (FOS). However, some levansucrase or inulinase enzymes can also use fructan as donor substrate in the abscence of sucrose or at a high fructan/sucrose ratio. Family GH68 includes levansucrase (sucrose:2,6-β-D-fructan 6-β-D-fructosyltransferase; EC 2.4.1.10), β-fructofuranosidase (EC 3.2.1.26), and inulosucrase (EC 2.4.1.9).<br />
<br />
== Kinetics and Mechanism ==<br />
Family GH68 enzymes as well as those included in <a href="/index.php/GH32" title="GH32" class="mw-redirect">GH32</a> are retaining enzymes <cite>1</cite>. The levansucrases from ''Bacillus subtilis'', ''Gluconacetobacter diazotrophicus'', and ''Streptococcus salivarius'' catalyze transfructosylation via a Ping-Pong mechanism involving the formation of a transient fructosyl-enzyme intermediate <cite>2 3 4 5</cite>. At low sucrose concentrations levansucrase functions as a hydrolase with water as acceptor, whereas at higher substrate concentrations it adds fructosyl units to a variety of acceptors including glucose, fructan and sucrose <cite>2</cite>. Bacterial levansucrases, whatever their origin, catalyze all these reactions but with different efficiency.<br />
<br />
== Catalytic Residues ==<br />
Retaining glycosidases catalyze hydrolysis in two steps involving a covalent glycosyl enzyme intermediate. The two invariant residues, responsible for the catalytic reaction in family GH68 enzymes, have first been identified experimentally in bacterial levansucrases as an aspartate located close to the N-terminus acting as the catalytic nucleophile and a glutamate acting as the general acid/base <cite>6 7</cite>. In addition, a conserved aspartate residue in the "Arg-Asp-Pro (RDP) motif" stabilizes the transition state <cite>5 7 8</cite>. The three equivalent acidic residues have been mutated in a β-fructofuranosidase from ''Arthrobacter globiformis'' IFO 3062 <cite>9</cite>, and in a levansucrase and a inulosucrase from ''Lactobacillus reuteri'' 121 <cite>10</cite>.<br />
<br />
== Three-dimensional structures ==<br />
Currently, only two different three dimensional structures of family GH68 enzymes have been solved. The first crystal structure was reported for the bacterial levansucrase (SacB) from ''Bacillus subtilis'' subsp. subtilis str. 168 <cite>6</cite>. The second one corresponds to levansucrase (LdsA) from ''Gluconacetobacter diazotrophicus'' SRT4 <cite>11</cite>. These structures display a 5-fold β-propeller topology, and therefore GH families 68 and 32 are combined in clan GH-J. On the other hand, a structural relationship of the catalytic core exists to family GH68 and family GH43, as predicted by detailed sequence analysis<cite>12</cite>. <br />
<br />
<br />
== Family Firsts ==<br />
;First stereochemistry determination: ''Bacillus subtilis'' levansucrase <cite>2</cite>.<br />
;First catalytic nucleophile identification: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
;First general acid/base residue identification: ''Zymomonas mobilis'' levansucrase <cite>7</cite>.<br />
;First stabilizing transition-state residue identification: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>8</cite>.<br />
;First prediction of a common beta-propeller catalytic domain in GH68 / clan GH-J: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>13 14</cite>.<br />
;First 3-D structure: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
<br />
== References ==<br />
<biblio><br />
#1 pmid=13174523<br />
#2 pmid=4206083<br />
#3 pmid=814002<br />
#4 pmid=7619044<br />
#5 pmid=10393084<br />
#6 pmid=14517548<br />
#7 pmid=12359071<br />
#8 pmid=9895294<br />
#9 pmid=16233623<br />
#10 pmid=14988011<br />
#11 pmid=15869470<br />
#12 pmid=11093261<br />
#13 pmid=9829697<br />
#14 pmid=11305239<br />
</biblio><br />
<br />
<br />
[[Category:Glycoside Hydrolase Families|GH068]]</div>Tirso Ponshttps://www.cazypedia.org/index.php?title=Glycoside_Hydrolase_Family_68&diff=3988Glycoside Hydrolase Family 682010-02-18T10:47:31Z<p>Tirso Pons: </p>
<hr />
<div><!-- CURATORS: Please replace the {{UnderConstruction}} tag below with {{CuratorApproved}} when the page is ready for wider public consumption --><br />
{{UnderConstruction}}<br />
* [[Author]]: ^^^Tirso Pons^^^ and ^^^Wim Van den Ende^^^<br />
* [[Responsible Curator]]: ^^^Wim Van den Ende^^^<br />
----<br />
<br />
<!-- The data in the table below should be updated by the Author/Curator according to current information on the family --><br />
<div style="float:right"><br />
{| {{Prettytable}} <br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH68'''<br />
|-<br />
|'''Clan''' <br />
|GH-J<br />
|-<br />
|'''Mechanism'''<br />
|retaining<br />
|-<br />
|'''Active site residues'''<br />
|known<br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br />
|-<br />
| colspan="2" |http://www.cazy.org/fam/GH68.html<br />
|}<br />
</div><br />
<!-- This is the end of the table --><br />
<br />
<br />
== Substrate specificities ==<br />
Glycoside hydrolase family GH68 contains enzymes that use sucrose as their preferential donor substrate and many of them can create very long levan or inulin-type of fructans, as well as fructooligosacharides (FOS). However, some levansucrase or inulinase enzymes can also use fructan as donor substrate in the abscence of sucrose or at a high fructan/sucrose ratio. Family GH68 includes levansucrase (sucrose:2,6-β-D-fructan 6-β-D-fructosyltransferase; EC 2.4.1.10), β-fructofuranosidase (EC 3.2.1.26), and inulosucrase (EC 2.4.1.9).<br />
<br />
== Kinetics and Mechanism ==<br />
Family GH68 enzymes as well as those included in GH32 are retaining enzymes <cite>1</cite>. The levansucrases from ''Bacillus subtilis'', ''Gluconacetobacter diazotrophicus'', and ''Streptococcus salivarius'' catalyze transfructosylation via a Ping-Pong mechanism involving the formation of a transient fructosyl-enzyme intermediate <cite>2 3 4 5</cite>. At low sucrose concentrations levansucrase functions as a hydrolase with water as acceptor, whereas at higher substrate concentrations it adds fructosyl units to a variety of acceptors including glucose, fructan and sucrose <cite>2</cite>. Bacterial levansucrases, whatever their origin, catalyze all these reactions but with different efficiency.<br />
<br />
== Catalytic Residues ==<br />
Retaining glycosidases catalyze hydrolysis in two steps involving a covalent glycosyl enzyme intermediate. The two invariant residues, responsible for the catalytic reaction in family GH68 enzymes, have first been identified experimentally in bacterial levansucrases as an aspartate located close to the N-terminus acting as the catalytic nucleophile and a glutamate acting as the general acid/base <cite>6 7</cite>. In addition, a conserved aspartate residue in the "Arg-Asp-Pro (RDP) motif" stabilizes the transition state <cite>5 7 8</cite>. The three equivalent acidic residues have been mutated in a β-fructofuranosidase from ''Arthrobacter globiformis'' IFO 3062 <cite>9</cite>, and in a levansucrase and a inulosucrase from ''Lactobacillus reuteri'' 121 <cite>10</cite>.<br />
<br />
== Three-dimensional structures ==<br />
Currently, only two different three dimensional structures of family GH68 enzymes have been solved. The first crystal structure was reported for the bacterial levansucrase (SacB) from ''Bacillus subtilis'' subsp. subtilis str. 168 <cite>6</cite>. The second one corresponds to levansucrase (LdsA) from ''Gluconacetobacter diazotrophicus'' SRT4 <cite>11</cite>. These structures display a 5-fold β-propeller topology, and therefore GH families 68 and 32 are combined in clan GH-J. On the other hand, a structural relationship of the catalytic core exists to family GH68 and family GH43, as predicted by detailed sequence analysis<cite>12</cite>. <br />
<br />
<br />
== Family Firsts ==<br />
;First stereochemistry determination: ''Bacillus subtilis'' levansucrase <cite>2</cite>.<br />
;First catalytic nucleophile identification: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
;First general acid/base residue identification: ''Zymomonas mobilis'' levansucrase <cite>7</cite>.<br />
;First stabilizing transition-state residue identification: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>8</cite>.<br />
;First prediction of a common beta-propeller catalytic domain in GH68 / clan GH-J: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>13 14</cite>.<br />
;First 3-D structure: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
<br />
== References ==<br />
<biblio><br />
#1 pmid=13174523<br />
#2 pmid=4206083<br />
#3 pmid=814002<br />
#4 pmid=7619044<br />
#5 pmid=10393084<br />
#6 pmid=14517548<br />
#7 pmid=12359071<br />
#8 pmid=9895294<br />
#9 pmid=16233623<br />
#10 pmid=14988011<br />
#11 pmid=15869470<br />
#12 pmid=11093261<br />
#13 pmid=9829697<br />
#14 pmid=11305239<br />
</biblio><br />
<br />
<br />
[[Category:Glycoside Hydrolase Families|GH068]]</div>Tirso Ponshttps://www.cazypedia.org/index.php?title=Glycoside_Hydrolase_Family_68&diff=3987Glycoside Hydrolase Family 682010-02-18T10:27:37Z<p>Tirso Pons: </p>
<hr />
<div><!-- CURATORS: Please replace the {{UnderConstruction}} tag below with {{CuratorApproved}} when the page is ready for wider public consumption --><br />
{{UnderConstruction}}<br />
* [[Author]]: ^^^Tirso Pons^^^ and ^^^Wim Van den Ende^^^<br />
* [[Responsible Curator]]: ^^^Wim Van den Ende^^^<br />
----<br />
<br />
<!-- The data in the table below should be updated by the Author/Curator according to current information on the family --><br />
<div style="float:right"><br />
{| {{Prettytable}} <br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH68'''<br />
|-<br />
|'''Clan''' <br />
|GH-J<br />
|-<br />
|'''Mechanism'''<br />
|retaining<br />
|-<br />
|'''Active site residues'''<br />
|known<br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br />
|-<br />
| colspan="2" |http://www.cazy.org/fam/GH68.html<br />
|}<br />
</div><br />
<!-- This is the end of the table --><br />
<br />
<br />
== Substrate specificities ==<br />
Glycoside hydrolase family GH68 contains enzymes that use sucrose as their preferential donor substrate and many of them can create very long levan or inulin-type of fructans, as well as fructooligosacharides (FOS). However, some levansucrase or inulinase enzymes can also use fructan as donor substrate in the abscence of sucrose or at a high fructan/sucrose ratio. Family GH68 includes levansucrase (sucrose:2,6-β-D-fructan 6-β-D-fructosyltransferase; EC 2.4.1.10), β-fructofuranosidase (EC 3.2.1.26), and inulosucrase (EC 2.4.1.9).<br />
<br />
== Kinetics and Mechanism ==<br />
Family GH68 enzymes as well as those included in GH32 are retaining enzymes <cite>1</cite>. The levansucrases from ''Bacillus subtilis'', ''Gluconacetobacter diazotrophicus'', and ''Streptococcus salivarius'' catalyze transfructosylation via a Ping-Pong mechanism involving the formation of a transient fructosyl-enzyme intermediate <cite>2 3 4 5</cite>. At low sucrose concentrations levansucrase functions as a hydrolase with water as acceptor, whereas at higher substrate concentrations it adds fructosyl units to a variety of acceptors including glucose, fructan and sucrose <cite>2</cite>. Bacterial levansucrases, whatever their origin, catalyze all these reactions but with different efficiency.<br />
<br />
== Catalytic Residues ==<br />
Retaining glycosidases catalyze hydrolysis in two steps involving a covalent glycosyl enzyme intermediate. The two invariant residues, responsible for the catalytic reaction in family GH68 enzymes, have first been identified experimentally in bacterial levansucrases as an aspartate located close to the N-terminus acting as the catalytic nucleophile and a glutamate acting as the general acid/base <cite>6 7</cite>. In addition, a conserved aspartate residue in the "Arg-Asp-Pro (RDP) motif" stabilizes the transition state <cite>5 7 8</cite>. The three equivalent acidic residues have been mutated in a β-fructofuranosidase from ''Arthrobacter globiformis'' IFO 3062 <cite>9</cite>, and in a levansucrase and a inulosucrase from ''Lactobacillus reuteri'' 121 <cite>10</cite>.<br />
<br />
== Three-dimensional structures ==<br />
Currently, only two different three dimensional structures of family GH68 enzymes have been solved. They have a 5-fold β-propeller topology. The first crystal structure was reported for the bacterial levansucrase (SacB) from ''Bacillus subtilis'' subsp. subtilis str. 168 <cite>6</cite>. The second one corresponds to levansucrase (LdsA) from ''Gluconacetobacter diazotrophicus'' SRT4 <cite>11</cite>. Families GH32 and GH68 are combined in clan GH-J.<br />
<br />
<br />
== Family Firsts ==<br />
;First stereochemistry determination: ''Bacillus subtilis'' levansucrase <cite>2</cite>.<br />
;First catalytic nucleophile identification: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
;First general acid/base residue identification: ''Zymomonas mobilis'' levansucrase <cite>7</cite>.<br />
;First stabilizing transition-state residue identification: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>8</cite>.<br />
;First prediction of a common beta-propeller catalytic domain in GH68 / clan GH-J: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>12 13</cite>.<br />
;First 3-D structure: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
<br />
== References ==<br />
<biblio><br />
#1 pmid=13174523<br />
#2 pmid=4206083<br />
#3 pmid=814002<br />
#4 pmid=7619044<br />
#5 pmid=10393084<br />
#6 pmid=14517548<br />
#7 pmid=12359071<br />
#8 pmid=9895294<br />
#9 pmid=16233623<br />
#10 pmid=14988011<br />
#11 pmid=15869470<br />
#12 pmid=9829697<br />
#13 pmid=11305239<br />
</biblio><br />
<br />
<br />
[[Category:Glycoside Hydrolase Families|GH068]]</div>Tirso Ponshttps://www.cazypedia.org/index.php?title=Glycoside_Hydrolase_Family_68&diff=3969Glycoside Hydrolase Family 682010-02-17T17:53:37Z<p>Tirso Pons: </p>
<hr />
<div><!-- CURATORS: Please replace the {{UnderConstruction}} tag below with {{CuratorApproved}} when the page is ready for wider public consumption --><br />
{{UnderConstruction}}<br />
* [[Author]]: ^^^Tirso Pons^^^ and ^^^Wim Van den Ende^^^<br />
* [[Responsible Curator]]: ^^^Wim Van den Ende^^^<br />
----<br />
<br />
<!-- The data in the table below should be updated by the Author/Curator according to current information on the family --><br />
<div style="float:right"><br />
{| {{Prettytable}} <br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH68'''<br />
|-<br />
|'''Clan''' <br />
|GH-J<br />
|-<br />
|'''Mechanism'''<br />
|retaining<br />
|-<br />
|'''Active site residues'''<br />
|known<br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br />
|-<br />
| colspan="2" |http://www.cazy.org/fam/GH68.html<br />
|}<br />
</div><br />
<!-- This is the end of the table --><br />
<br />
<br />
== Substrate specificities ==<br />
Glycoside hydrolase family GH68 contains enzymes that use sucrose as their preferential donor substrate and many of them can create very long levan or inulin-type of fructans, as well as fructooligosacharides (FOS). Family GH68 includes levansucrase (sucrose:2,6-β-D-fructan 6-β-D-fructosyltransferase; EC 2.4.1.10), β-fructofuranosidase (EC 3.2.1.26), and inulosucrase (EC 2.4.1.9).<br />
<br />
== Kinetics and Mechanism ==<br />
Family GH68 enzymes as well as those included in GH32 are retaining enzymes <cite>1</cite>. The levansucrases from ''Bacillus subtilis'', ''Gluconacetobacter diazotrophicus'', and ''Streptococcus salivarius'' catalyze transfructosylation via a Ping-Pong mechanism involving the formation of a transient fructosyl-enzyme intermediate <cite>2 3 4 5</cite>. At low sucrose concentrations levansucrase functions as a hydrolase with water as acceptor, whereas at higher substrate concentrations it adds fructosyl units to a variety of acceptors including glucose, fructan and sucrose <cite>2</cite>. Bacterial levansucrases, whatever their origin, catalyze all these reactions but with different efficiency.<br />
<br />
== Catalytic Residues ==<br />
Retaining glycosidases catalyze hydrolysis in two steps involving a covalent glycosyl enzyme intermediate. The two invariant residues, responsible for the catalytic reaction in family GH68 enzymes, have first been identified experimentally in bacterial levansucrases as an aspartate located close to the N-terminus acting as the catalytic nucleophile and a glutamate acting as the general acid/base <cite>6 7</cite>. In addition, a conserved aspartate residue in the "Arg-Asp-Pro (RDP) motif" stabilizes the transition state <cite>5 7 8</cite>. The three equivalent acidic residues have been also mutated in β-fructofuranosidase from ''Arthrobacter globiformis'' IFO 3062 <cite>9</cite>, and levansucrase and inulosucrase from ''Lactobacillus reuteri'' 121 <cite>10</cite>.<br />
<br />
== Three-dimensional structures ==<br />
Currently, only two different three dimensional structures of family GH68 enzymes have been solved. The first crystal structure was reported for the bacterial levansucrase (SacB) from ''Bacillus subtilis'' subsp. subtilis str. 168 <cite>6</cite>. The second one corresponds to levansucrase (LdsA) from ''Gluconacetobacter diazotrophicus'' SRT4 <cite>11</cite>. Families GH32 and GH68 are combined in clan GH-J.<br />
<br />
<br />
== Family Firsts ==<br />
;First stereochemistry determination: ''Bacillus subtilis'' levansucrase <cite>2</cite>.<br />
;First catalytic nucleophile identification: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
;First general acid/base residue identification: ''Zymomonas mobilis'' levansucrase <cite>7</cite>.<br />
;First stabilizing transition-state residue identification: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>8</cite>.<br />
;First prediction of a common beta-propeller catalytic domain in GH68 / clan GH-J: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>12 13</cite>.<br />
;First 3-D structure: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
<br />
== References ==<br />
<biblio><br />
#1 pmid=13174523<br />
#2 pmid=4206083<br />
#3 pmid=814002<br />
#4 pmid=7619044<br />
#5 pmid=10393084<br />
#6 pmid=14517548<br />
#7 pmid=12359071<br />
#8 pmid=9895294<br />
#9 pmid=16233623<br />
#10 pmid=14988011<br />
#11 pmid=15869470<br />
#12 pmid=9829697<br />
#13 pmid=11305239<br />
</biblio><br />
<br />
<br />
[[Category:Glycoside Hydrolase Families|GH068]]</div>Tirso Ponshttps://www.cazypedia.org/index.php?title=Glycoside_Hydrolase_Family_68&diff=3961Glycoside Hydrolase Family 682010-02-17T16:14:57Z<p>Tirso Pons: </p>
<hr />
<div><!-- CURATORS: Please replace the {{UnderConstruction}} tag below with {{CuratorApproved}} when the page is ready for wider public consumption --><br />
{{UnderConstruction}}<br />
* [[Author]]: ^^^Tirso Pons^^^ and ^^^Wim Van den Ende^^^<br />
* [[Responsible Curator]]: ^^^Wim Van den Ende^^^<br />
----<br />
<br />
<!-- The data in the table below should be updated by the Author/Curator according to current information on the family --><br />
<div style="float:right"><br />
{| {{Prettytable}} <br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH68'''<br />
|-<br />
|'''Clan''' <br />
|GH-J<br />
|-<br />
|'''Mechanism'''<br />
|retaining<br />
|-<br />
|'''Active site residues'''<br />
|known<br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br />
|-<br />
| colspan="2" |http://www.cazy.org/fam/GH68.html<br />
|}<br />
</div><br />
<!-- This is the end of the table --><br />
<br />
<br />
== Substrate specificities ==<br />
Glycoside hydrolase family GH68 contains enzymes that use sucrose as their preferential donor substrate and many of them can create very long levan or inulin-type of fructans. Family GH68 includes levansucrase (sucrose:2,6-β-D-fructan 6-β-D-fructosyltransferase; EC 2.4.1.10), β-fructofuranosidase (EC 3.2.1.26), and inulosucrase (EC 2.4.1.9).<br />
<br />
== Kinetics and Mechanism ==<br />
Family GH68 enzymes as well as those included in GH32 are retaining enzymes <cite>1</cite>. The levansucrases from ''Bacillus subtilis'', ''Gluconacetobacter diazotrophicus'', and ''Streptococcus salivarius'' catalyze transfructosylation via a Ping-Pong mechanism involving the formation of a transient fructosyl-enzyme intermediate <cite>2 3 4 5</cite>. At low sucrose concentrations levansucrase functions as a hydrolase with water as acceptor, whereas at higher substrate concentrations it adds fructosyl units to a variety of acceptors including glucose, fructan and sucrose <cite>2</cite>. Bacterial levansucrases, whatever their origin, catalyze all these reactions but with different efficiency.<br />
<br />
== Catalytic Residues ==<br />
Retaining glycosidases catalyze hydrolysis in two steps involving a covalent glycosyl enzyme intermediate. The two invariant residues, responsible for the catalytic reaction in family GH68 enzymes, have first been identified experimentally in bacterial levansucrases as an aspartate located close to the N-terminus acting as the catalytic nucleophile and a glutamate acting as the general acid/base <cite>6 7</cite>. In addition, a conserved aspartate residue in the "Arg-Asp-Pro (RDP) motif" stabilizes the transition state <cite>5 7 8</cite>. The three equivalent acidic residues have been also mutated in β-fructofuranosidase from ''Arthrobacter globiformis'' IFO 3062 <cite>9</cite>, and levansucrase and inulosucrase from ''Lactobacillus reuteri'' 121 <cite>10</cite>.<br />
<br />
== Three-dimensional structures ==<br />
Currently, only two different three dimensional structures of family GH68 enzymes have been solved. The first crystal structure was reported for the bacterial levansucrase (SacB) from ''Bacillus subtilis'' subsp. subtilis str. 168 <cite>6</cite>. The second one corresponds to levansucrase (LdsA) from ''Gluconacetobacter diazotrophicus'' SRT4 <cite>11</cite>. Families GH32 and GH68 are combined in clan GH-J.<br />
<br />
<br />
== Family Firsts ==<br />
;First stereochemistry determination: ''Bacillus subtilis'' levansucrase <cite>2</cite>.<br />
;First catalytic nucleophile identification: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
;First general acid/base residue identification: ''Zymomonas mobilis'' levansucrase <cite>7</cite>.<br />
;First stabilizing transition-state residue identification: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>8</cite>.<br />
;First prediction of a common beta-propeller catalytic domain in GH68 / clan GH-J: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>12 13</cite>.<br />
;First 3-D structure: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
<br />
== References ==<br />
<biblio><br />
#1 pmid=13174523<br />
#2 pmid=4206083<br />
#3 pmid=814002<br />
#4 pmid=7619044<br />
#5 pmid=10393084<br />
#6 pmid=14517548<br />
#7 pmid=12359071<br />
#8 pmid=9895294<br />
#9 pmid=16233623<br />
#10 pmid=14988011<br />
#11 pmid=15869470<br />
#12 pmid=9829697<br />
#13 pmid=11305239<br />
</biblio><br />
<br />
<br />
[[Category:Glycoside Hydrolase Families|GH068]]</div>Tirso Ponshttps://www.cazypedia.org/index.php?title=Glycoside_Hydrolase_Family_68&diff=3960Glycoside Hydrolase Family 682010-02-17T16:13:35Z<p>Tirso Pons: </p>
<hr />
<div><!-- CURATORS: Please replace the {{UnderConstruction}} tag below with {{CuratorApproved}} when the page is ready for wider public consumption --><br />
{{UnderConstruction}}<br />
* [[Author]]: ^^^Tirso Pons^^^ and ^^^Wim Van den Ende^^^<br />
* [[Responsible Curator]]: ^^^Wim Van den Ende^^^<br />
----<br />
<br />
<!-- The data in the table below should be updated by the Author/Curator according to current information on the family --><br />
<div style="float:right"><br />
{| {{Prettytable}} <br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH68'''<br />
|-<br />
|'''Clan''' <br />
|GH-J<br />
|-<br />
|'''Mechanism'''<br />
|retaining<br />
|-<br />
|'''Active site residues'''<br />
|known<br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br />
|-<br />
| colspan="2" |http://www.cazy.org/fam/GH68.html<br />
|}<br />
</div><br />
<!-- This is the end of the table --><br />
<br />
<br />
== Substrate specificities ==<br />
Glycoside hydrolase family GH68 contains enzymes that use sucrose as their preferential donor substrate and many of them can create very long levan or inulin-type of fructans. Family GH68 includes levansucrase (sucrose:2,6-β-D-fructan 6-β-D-fructosyltransferase; EC 2.4.1.10), β-fructofuranosidase (EC 3.2.1.26), and inulosucrase (EC 2.4.1.9).<br />
<br />
== Kinetics and Mechanism ==<br />
Family GH68 enzymes as well as those included in GH32 are retaining enzymes <cite>1</cite>. The levansucrases from ''Bacillus subtilis'', ''Gluconacetobacter diazotrophicus'', and ''Streptococcus salivarius'' catalyze transfructosylation via a Ping-Pong mechanism involving the formation of a transient fructosyl-enzyme intermediate <cite>2 3 4 5</cite>. At low sucrose concentrations levansucrase functions as a hydrolase with water as acceptor, whereas at higher substrate concentrations it adds fructosyl units to a variety of acceptors including glucose, fructan and sucrose <cite>2</cite>. Bacterial levansucrases, whatever their origin, catalyze all these reactions but with different efficiency.<br />
<br />
== Catalytic Residues ==<br />
Retaining glycosidases catalyze hydrolysis in two steps involving a covalent glycosyl enzyme intermediate. The two invariant residues, responsible for the catalytic reaction in family GH68 enzymes, have first been identified experimentally in bacterial levansucrases as an aspartate located close to the N-terminus acting as the catalytic nucleophile and a glutamate acting as the general acid/base <cite>6 7</cite>. In addition, a conserved aspartate residue in the "Arg-Asp-Pro (RDP) motif" stabilizes the transition state <cite>5 7 8</cite>. The three equivalent acidic residues have been also mutated in β-fructofuranosidase from ''Arthrobacter globiformis'' IFO 3062 <cite>9</cite>, and levansucrase and inulosucrase from "Lactobacillus reuteri" 121 <cite>10</cite>.<br />
<br />
== Three-dimensional structures ==<br />
Currently, only two different three dimensional structures of family GH68 enzymes have been solved. The first crystal structure was reported for the bacterial levansucrase (SacB) from ''Bacillus subtilis'' subsp. subtilis str. 168 <cite>6</cite>. The second one corresponds to levansucrase (LdsA) from ''Gluconacetobacter diazotrophicus'' SRT4 <cite>11</cite>. Families GH32 and GH68 are combined in clan GH-J.<br />
<br />
<br />
== Family Firsts ==<br />
;First stereochemistry determination: ''Bacillus subtilis'' levansucrase <cite>2</cite>.<br />
;First catalytic nucleophile identification: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
;First general acid/base residue identification: ''Zymomonas mobilis'' levansucrase <cite>7</cite>.<br />
;First stabilizing transition-state residue identification: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>8</cite>.<br />
;First prediction of a common beta-propeller catalytic domain in GH68 / clan GH-J: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>12 13</cite>.<br />
;First 3-D structure: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
<br />
== References ==<br />
<biblio><br />
#1 pmid=13174523<br />
#2 pmid=4206083<br />
#3 pmid=814002<br />
#4 pmid=7619044<br />
#5 pmid=10393084<br />
#6 pmid=14517548<br />
#7 pmid=12359071<br />
#8 pmid=9895294<br />
#9 pmid=16233623<br />
#10 pmid=14988011<br />
#11 pmid=15869470<br />
#12 pmid=9829697<br />
#13 pmid=11305239<br />
</biblio><br />
<br />
<br />
[[Category:Glycoside Hydrolase Families|GH068]]</div>Tirso Ponshttps://www.cazypedia.org/index.php?title=Glycoside_Hydrolase_Family_68&diff=3959Glycoside Hydrolase Family 682010-02-17T15:40:30Z<p>Tirso Pons: </p>
<hr />
<div><!-- CURATORS: Please replace the {{UnderConstruction}} tag below with {{CuratorApproved}} when the page is ready for wider public consumption --><br />
{{UnderConstruction}}<br />
* [[Author]]: ^^^Tirso Pons^^^ and ^^^Wim Van den Ende^^^<br />
* [[Responsible Curator]]: ^^^Wim Van den Ende^^^<br />
----<br />
<br />
<!-- The data in the table below should be updated by the Author/Curator according to current information on the family --><br />
<div style="float:right"><br />
{| {{Prettytable}} <br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH68'''<br />
|-<br />
|'''Clan''' <br />
|GH-J<br />
|-<br />
|'''Mechanism'''<br />
|retaining<br />
|-<br />
|'''Active site residues'''<br />
|known<br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br />
|-<br />
| colspan="2" |http://www.cazy.org/fam/GH68.html<br />
|}<br />
</div><br />
<!-- This is the end of the table --><br />
<br />
<br />
== Substrate specificities ==<br />
Glycoside hydrolase family GH68 contains enzymes that use sucrose as their preferential donor substrate and many of them can create very long levan or inulin-type of fructans. Family GH68 includes levansucrase (sucrose:2,6-β-D-fructan 6-β-D-fructosyltransferase; EC 2.4.1.10), β-fructofuranosidase (EC 3.2.1.26), and inulosucrase (EC 2.4.1.9).<br />
<br />
== Kinetics and Mechanism ==<br />
Family GH68 enzymes are retaining enzymes <cite>1</cite>. The levansucrases from ''Bacillus subtilis'', ''Gluconacetobacter diazotrophicus'', and ''Streptococcus salivarius'' catalyze transfructosylation via a Ping-Pong mechanism involving the formation of a transient fructosyl-enzyme intermediate <cite>2 3 4 5</cite>. At low sucrose concentrations levansucrase functions as a hydrolase with water as acceptor, whereas at higher substrate concentrations it adds fructosyl units to a variety of acceptors including glucose, fructan and sucrose <cite>2</cite>. Bacterial levansucrases, whatever their origin, catalyze all these reactions but with different efficiency.<br />
<br />
== Catalytic Residues ==<br />
Retaining glycosidases catalyze hydrolysis in two steps involving a covalent glycosyl enzyme intermediate. The two invariant residues, responsible for the catalytic reaction in family GH68 enzymes, have first been identified experimentally in bacterial levansucrases as an aspartate located close to the N-terminus acting as the catalytic nucleophile and a glutamate acting as the general acid/base <cite>6 7</cite>. In addition, a conserved aspartate residue in the "Arg-Asp-Pro (RDP) motif" stabilizes the transition state <cite>5 7 8</cite>. The three equivalent acidic residues have been also mutated in β-fructofuranosidase from ''Arthrobacter globiformis'' IFO 3062 <cite>9</cite>.<br />
<br />
== Three-dimensional structures ==<br />
Currently, only two different three dimensional structures of family GH68 enzymes have been solved. The first crystal structure was reported for the bacterial levansucrase (SacB) from ''Bacillus subtilis'' subsp. subtilis str. 168 <cite>6</cite>. The second one corresponds to levansucrase (LdsA) from ''Gluconacetobacter diazotrophicus'' SRT4 <cite>10</cite>. Families GH32 and GH68 are combined in clan GH-J.<br />
<br />
<br />
== Family Firsts ==<br />
;First stereochemistry determination: ''Bacillus subtilis'' levansucrase <cite>2</cite>.<br />
;First catalytic nucleophile identification: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
;First general acid/base residue identification: ''Zymomonas mobilis'' levansucrase <cite>7</cite>.<br />
;First stabilizing transition-state residue identification: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>8</cite>.<br />
;First prediction of a common beta-propeller catalytic domain in GH68 / clan GH-J: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>11 12</cite>.<br />
;First 3-D structure: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
<br />
== References ==<br />
<biblio><br />
#1 pmid=13174523<br />
#2 pmid=4206083<br />
#3 pmid=814002<br />
#4 pmid=7619044<br />
#5 pmid=10393084<br />
#6 pmid=14517548<br />
#7 pmid=12359071<br />
#8 pmid=9895294<br />
#9 pmid=16233623<br />
#10 pmid=15869470<br />
#11 pmid=9829697<br />
#12 pmid=11305239<br />
</biblio><br />
<br />
<br />
[[Category:Glycoside Hydrolase Families|GH068]]</div>Tirso Ponshttps://www.cazypedia.org/index.php?title=Glycoside_Hydrolase_Family_68&diff=3958Glycoside Hydrolase Family 682010-02-17T15:02:18Z<p>Tirso Pons: </p>
<hr />
<div><!-- CURATORS: Please replace the {{UnderConstruction}} tag below with {{CuratorApproved}} when the page is ready for wider public consumption --><br />
{{UnderConstruction}}<br />
* [[Author]]: ^^^Tirso Pons^^^ and ^^^Wim Van den Ende^^^<br />
* [[Responsible Curator]]: ^^^Wim Van den Ende^^^<br />
----<br />
<br />
<!-- The data in the table below should be updated by the Author/Curator according to current information on the family --><br />
<div style="float:right"><br />
{| {{Prettytable}} <br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH68'''<br />
|-<br />
|'''Clan''' <br />
|GH-J<br />
|-<br />
|'''Mechanism'''<br />
|retaining<br />
|-<br />
|'''Active site residues'''<br />
|known<br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br />
|-<br />
| colspan="2" |http://www.cazy.org/fam/GH68.html<br />
|}<br />
</div><br />
<!-- This is the end of the table --><br />
<br />
<br />
== Substrate specificities ==<br />
Glycoside hydrolase family GH68 contains enzymes that use sucrose as their preferential donor substrate and many of them can create very long levan or inulin-type of fructans. Family GH68 includes levansucrase (sucrose:2,6-β-D-fructan 6-β-D-fructosyltransferase; EC 2.4.1.10), β-fructofuranosidase (EC 3.2.1.26), and inulosucrase (EC 2.4.1.9).<br />
<br />
== Kinetics and Mechanism ==<br />
Family GH68 enzymes are retaining enzymes, as first shown by Koshland and Stein by performing the reaction in <sup>18</sup>O-labeled water and determining the <sup>18</sup>O content of the products <cite>1</cite>. The levansucrases from ''Bacillus subtilis'', ''Gluconacetobacter diazotrophicus'', and ''Streptococcus salivarius'' catalyze transfructosylation via a Ping-Pong mechanism involving the formation of a transient fructosyl-enzyme intermediate <cite>2 3 4 5</cite>. At low sucrose concentrations levansucrase functions as a hydrolase with water as acceptor, whereas at higher substrate concentrations it adds fructosyl units to a variety of acceptors including glucose, fructan and sucrose <cite>2</cite>. Bacterial levansucrases, whatever their origin, catalyze all these reactions but with different efficiency.<br />
<br />
== Catalytic Residues ==<br />
Retaining glycosidases catalyze hydrolysis in two steps involving a covalent glycosyl enzyme intermediate. The two invariant residues, responsible for the catalytic reaction in family GH68 enzymes, have first been identified experimentally in bacterial levansucrases as an aspartate located close to the N-terminus acting as the catalytic nucleophile and a glutamate acting as the general acid/base <cite>6 7</cite>. In addition, a conserved aspartate residue in the "Arg-Asp-Pro (RDP) motif" stabilizes the transition state <cite>5 7 8</cite>. The three equivalent acidic residues have been also mutated in β-fructofuranosidase from ''Arthrobacter globiformis'' IFO 3062 <cite>9</cite>.<br />
<br />
== Three-dimensional structures ==<br />
Currently, only two different three dimensional structures of family GH68 enzymes have been solved. The first crystal structure was reported for the bacterial levansucrase (SacB) from ''Bacillus subtilis'' subsp. subtilis str. 168 <cite>6</cite>. The second one corresponds to levansucrase (LdsA) from ''Gluconacetobacter diazotrophicus'' SRT4 <cite>10</cite>. Families GH32 and GH68 are combined in clan GH-J.<br />
<br />
<br />
== Family Firsts ==<br />
;First stereochemistry determination: ''Bacillus subtilis'' levansucrase <cite>2</cite>.<br />
;First catalytic nucleophile identification: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
;First general acid/base residue identification: ''Zymomonas mobilis'' levansucrase <cite>7</cite>.<br />
;First stabilizing transition-state residue identification: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>8</cite>.<br />
;First prediction of a common beta-propeller catalytic domain in GH68 / clan GH-J: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>11 12</cite>.<br />
;First 3-D structure: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
<br />
== References ==<br />
<biblio><br />
#1 pmid=13174523<br />
#2 pmid=4206083<br />
#3 pmid=814002<br />
#4 pmid=7619044<br />
#5 pmid=10393084<br />
#6 pmid=14517548<br />
#7 pmid=12359071<br />
#8 pmid=9895294<br />
#9 pmid=16233623<br />
#10 pmid=15869470<br />
#11 pmid=9829697<br />
#12 pmid=11305239<br />
</biblio><br />
<br />
<br />
[[Category:Glycoside Hydrolase Families|GH068]]</div>Tirso Ponshttps://www.cazypedia.org/index.php?title=Glycoside_Hydrolase_Family_68&diff=3957Glycoside Hydrolase Family 682010-02-17T14:28:00Z<p>Tirso Pons: </p>
<hr />
<div><!-- CURATORS: Please replace the {{UnderConstruction}} tag below with {{CuratorApproved}} when the page is ready for wider public consumption --><br />
{{UnderConstruction}}<br />
* [[Author]]: ^^^Tirso Pons^^^ and ^^^Wim Van den Ende^^^<br />
* [[Responsible Curator]]: ^^^Wim Van den Ende^^^<br />
----<br />
<br />
<!-- The data in the table below should be updated by the Author/Curator according to current information on the family --><br />
<div style="float:right"><br />
{| {{Prettytable}} <br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH68'''<br />
|-<br />
|'''Clan''' <br />
|GH-J<br />
|-<br />
|'''Mechanism'''<br />
|retaining<br />
|-<br />
|'''Active site residues'''<br />
|known<br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br />
|-<br />
| colspan="2" |http://www.cazy.org/fam/GH68.html<br />
|}<br />
</div><br />
<!-- This is the end of the table --><br />
<br />
<br />
== Substrate specificities ==<br />
Glycoside hydrolase family GH68 contains enzymes that hydrolyze fructose containing polysaccharides such as levansucrase (sucrose:2,6-β-D-fructan 6-β-D-fructosyltransferase; EC 2.4.1.10); β-fructofuranosidase (EC 3.2.1.26); and inulosucrase (EC 2.4.1.9)<br />
<br />
== Kinetics and Mechanism ==<br />
Family GH68 enzymes are retaining enzymes, as first shown by Koshland and Stein by performing the reaction in <sup>18</sup>O-labeled water and determining the <sup>18</sup>O content of the products <cite>1</cite>. The levansucrases from ''Bacillus subtilis'', ''Gluconacetobacter diazotrophicus'', and ''Streptococcus salivarius'' catalyze transfructosylation via a Ping-Pong mechanism involving the formation of a transient fructosyl-enzyme intermediate <cite>2 3 4 5</cite>. At low sucrose concentrations levansucrase functions as a hydrolase with water as acceptor, whereas at higher substrate concentrations it adds fructosyl units to a variety of acceptors including glucose, fructan and sucrose <cite>2</cite>.<br />
Bacterial levansucrases, whatever their origin, catalyze all these reactions but with different efficiency.<br />
<br />
== Catalytic Residues ==<br />
Retaining glycosidases catalyze hydrolysis in two steps involving a covalent glycosyl enzyme intermediate. The two invariant residues, responsible for the catalytic reaction in family GH68 enzymes, have first been identified experimentally in bacterial levansucrases as an aspartate located close to the N-terminus acting as the catalytic nucleophile and a glutamate acting as the general acid/base <cite>6 7</cite>. In addition, a conserved aspartate residue in the "Arg-Asp-Pro (RDP) motif" stabilize the transition state <cite>5 7 8</cite>. The three equivalent acidic residues have been also mutated in β-fructofuranosidase from ''Arthrobacter globiformis'' IFO 3062 <cite>9</cite>.<br />
<br />
== Three-dimensional structures ==<br />
Currently, only two different three dimensional structures of family GH68 enzymes have been solved so far. The first crystal structure was reported for the bacterial levansucrase (SacB) from ''Bacillus subtilis'' subsp. subtilis str. 168 <cite>6</cite>. The second one corresponds to levansucrase (LdsA) from ''Gluconacetobacter diazotrophicus'' SRT4 <cite>10</cite>.<br />
<br />
<br />
== Family Firsts ==<br />
;First stereochemistry determination: ''Bacillus subtilis'' levansucrase <cite>2</cite>.<br />
;First catalytic nucleophile identification: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
;First general acid/base residue identification: ''Zymomonas mobilis'' levansucrase <cite>7</cite>.<br />
;First stabilizing transition-state residue identification: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>8</cite>.<br />
;First prediction of a common beta-propeller catalytic domain in GH68 / clan GH-J: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>11 12</cite>.<br />
;First 3-D structure: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
<br />
== References ==<br />
<biblio><br />
#1 pmid=13174523<br />
#2 pmid=4206083<br />
#3 pmid=814002<br />
#4 pmid=7619044<br />
#5 pmid=10393084<br />
#6 pmid=14517548<br />
#7 pmid=12359071<br />
#8 pmid=9895294<br />
#9 pmid=16233623<br />
#10 pmid=15869470<br />
#11 pmid=9829697<br />
#12 pmid=11305239<br />
</biblio><br />
<br />
<br />
[[Category:Glycoside Hydrolase Families|GH068]]</div>Tirso Ponshttps://www.cazypedia.org/index.php?title=Glycoside_Hydrolase_Family_68&diff=3952Glycoside Hydrolase Family 682010-02-17T13:56:14Z<p>Tirso Pons: </p>
<hr />
<div><!-- CURATORS: Please replace the {{UnderConstruction}} tag below with {{CuratorApproved}} when the page is ready for wider public consumption --><br />
{{UnderConstruction}}<br />
* [[Author]]: ^^^Tirso Pons^^^ and ^^^Wim Van den Ende^^^<br />
* [[Responsible Curator]]: ^^^Wim Van den Ende^^^<br />
----<br />
<br />
<!-- The data in the table below should be updated by the Author/Curator according to current information on the family --><br />
<div style="float:right"><br />
{| {{Prettytable}} <br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH68'''<br />
|-<br />
|'''Clan''' <br />
|GH-J<br />
|-<br />
|'''Mechanism'''<br />
|retaining<br />
|-<br />
|'''Active site residues'''<br />
|known<br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br />
|-<br />
| colspan="2" |http://www.cazy.org/fam/GH68.html<br />
|}<br />
</div><br />
<!-- This is the end of the table --><br />
<br />
<br />
== Substrate specificities ==<br />
Glycoside hydrolase family GH68 contains enzymes that hydrolyze fructose containing polysaccharides such as levansucrase (sucrose:2,6-β-D-fructan 6-β-D-fructosyltransferase; EC 2.4.1.10); β-fructofuranosidase (EC 3.2.1.26); and inulosucrase (EC 2.4.1.9)<br />
<br />
== Kinetics and Mechanism ==<br />
Family GH68 enzymes are retaining enzymes, as first shown by Koshland and Stein by performing the reaction in <sup>18</sup>O-labeled water and determining the <sup>18</sup>O content of the products <cite>1</cite>. The levansucrases from ''Bacillus subtilis'', ''Gluconacetobacter diazotrophicus'', and ''Streptococcus salivarius'' catalyze transfructosylation via a Ping-Pong mechanism involving the formation of a transient fructosyl-enzyme intermediate <cite>2 3 4 5</cite>. At low sucrose concentrations levansucrase functions as a hydrolase with water as acceptor, whereas at higher substrate concentrations it adds fructosyl units to a variety of acceptors including glucose, fructan and sucrose <cite>2</cite>.<br />
Bacterial levansucrases, whatever their origin, catalyze all these reactions but with different efficiency.<br />
<br />
== Catalytic Residues ==<br />
Retaining glycosidases catalyze hydrolysis in two steps involving a covalent glycosyl enzyme intermediate. The two invariant residues, responsible for the catalytic reaction in family GH68 enzymes, have first been identified experimentally in bacterial levansucrases as an aspartate located close to the N-terminus acting as the catalytic nucleophile and a glutamate acting as the general acid/base <cite>6 7</cite>. In addition, a conserved aspartate residue in the "Arg-Asp-Pro (RDP) motif" stabilize the transition state <cite>5 7 8</cite>. The three equivalent residues have been also mutated in β-fructofuranosidase from ''Arthrobacter globiformis'' IFO 3062 <cite>9</cite>.<br />
<br />
== Three-dimensional structures ==<br />
Currently, only two different three dimensional structures of family GH68 enzymes have been solved so far. The first crystal structure was reported for the bacterial levansucrase (SacB) from ''Bacillus subtilis'' subsp. subtilis str. 168 <cite>6</cite>. The second one corresponds to levansucrase (LdsA) from ''Gluconacetobacter diazotrophicus'' SRT4 <cite>10</cite>.<br />
<br />
<br />
== Family Firsts ==<br />
;First stereochemistry determination: ''Bacillus subtilis'' levansucrase <cite>2</cite>.<br />
;First catalytic nucleophile identification: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
;First general acid/base residue identification: ''Zymomonas mobilis'' levansucrase <cite>7</cite>.<br />
;First stabilizing transition-state residue identification: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>8</cite>.<br />
;First prediction of a common beta-propeller catalytic domain in GH68 / clan GH-J: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>11 12</cite>.<br />
;First 3-D structure: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
<br />
== References ==<br />
<biblio><br />
#1 pmid=13174523<br />
#2 pmid=4206083<br />
#3 pmid=814002<br />
#4 pmid=7619044<br />
#5 pmid=10393084<br />
#6 pmid=14517548<br />
#7 pmid=12359071<br />
#8 pmid=9895294<br />
#9 pmid=16233623<br />
#10 pmid=15869470<br />
#11 pmid=9829697<br />
#12 pmid=11305239<br />
</biblio><br />
<br />
<br />
[[Category:Glycoside Hydrolase Families|GH068]]</div>Tirso Ponshttps://www.cazypedia.org/index.php?title=Glycoside_Hydrolase_Family_68&diff=3948Glycoside Hydrolase Family 682010-02-17T13:22:40Z<p>Tirso Pons: </p>
<hr />
<div><!-- CURATORS: Please replace the {{UnderConstruction}} tag below with {{CuratorApproved}} when the page is ready for wider public consumption --><br />
{{UnderConstruction}}<br />
* [[Author]]: ^^^Tirso Pons^^^ and ^^^Wim Van den Ende^^^<br />
* [[Responsible Curator]]: ^^^Wim Van den Ende^^^<br />
----<br />
<br />
<!-- The data in the table below should be updated by the Author/Curator according to current information on the family --><br />
<div style="float:right"><br />
{| {{Prettytable}} <br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH68'''<br />
|-<br />
|'''Clan''' <br />
|GH-J<br />
|-<br />
|'''Mechanism'''<br />
|retaining<br />
|-<br />
|'''Active site residues'''<br />
|known<br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br />
|-<br />
| colspan="2" |http://www.cazy.org/fam/GH68.html<br />
|}<br />
</div><br />
<!-- This is the end of the table --><br />
<br />
<br />
== Substrate specificities ==<br />
Glycoside hydrolase family GH68 contains enzymes that hydrolyze fructose containing polysaccharides such as levansucrase (sucrose:2,6-β-D-fructan 6-β-D-fructosyltransferase; EC 2.4.1.10); β-fructofuranosidase (EC 3.2.1.26); and inulosucrase (EC 2.4.1.9)<br />
<br />
== Kinetics and Mechanism ==<br />
Family GH68 enzymes are retaining enzymes, as first shown by Koshland and Stein by performing the reaction in <sup>18</sup>O-labeled water and determining the <sup>18</sup>O content of the products <cite>1</cite>. The levansucrases from ''Bacillus subtilis'', ''Gluconacetobacter diazotrophicus'', and ''Streptococcus salivarius'' catalyze transfructosylation via a Ping-Pong mechanism involving the formation of a transient fructosyl-enzyme intermediate <cite>2 3 4 5</cite>. At low sucrose concentrations levansucrase functions as a hydrolase with water as acceptor, whereas at higher substrate concentrations it adds fructosyl units to a variety of acceptors including glucose, fructan and sucrose <cite>2</cite>.<br />
Bacterial levansucrases, whatever their origin, catalyze all these reactions but with different efficiency.<br />
<br />
== Catalytic Residues ==<br />
Retaining glycosidases catalyze hydrolysis in two steps involving a covalent glycosyl enzyme intermediate. The two invariant residues, responsible for the catalytic reaction in family GH68 enzymes, have first been identified experimentally in bacterial levansucrases as an aspartate located close to the N-terminus acting as the catalytic nucleophile and a glutamate acting as the general acid/base <cite>6 7</cite>. In addition, a conserved aspartate residue in the "Arg-Asp-Pro (RDP) motif" stabilize the transition state <cite>5 7 8</cite>.<br />
<br />
== Three-dimensional structures ==<br />
Currently, only two different three dimensional structures of family GH68 enzymes have been solved so far. The first crystal structure was reported for the bacterial levansucrase (SacB) from ''Bacillus subtilis'' subsp. subtilis str. 168 <cite>6</cite>. The second one corresponds to levansucrase (LdsA) from ''Gluconacetobacter diazotrophicus'' SRT4 <cite>9</cite>.<br />
<br />
<br />
== Family Firsts ==<br />
;First stereochemistry determination: ''Bacillus subtilis'' levansucrase <cite>2</cite>.<br />
;First catalytic nucleophile identification: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
;First general acid/base residue identification: ''Zymomonas mobilis'' levansucrase <cite>7</cite>.<br />
;First stabilizing transition-state residue identification: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>8</cite>.<br />
;First prediction of a common beta-propeller catalytic domain in GH68 / clan GH-J: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>10 11</cite>.<br />
;First 3-D structure: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
<br />
== References ==<br />
<biblio><br />
#1 pmid=13174523<br />
#2 pmid=4206083<br />
#3 pmid=814002<br />
#4 pmid=7619044<br />
#5 pmid=10393084<br />
#6 pmid=14517548<br />
#7 pmid=12359071<br />
#8 pmid=9895294<br />
#9 pmid=15869470<br />
#10 pmid=9829697<br />
#11 pmid=11305239<br />
</biblio><br />
<br />
<br />
[[Category:Glycoside Hydrolase Families|GH068]]</div>Tirso Ponshttps://www.cazypedia.org/index.php?title=Glycoside_Hydrolase_Family_68&diff=3947Glycoside Hydrolase Family 682010-02-17T13:21:27Z<p>Tirso Pons: </p>
<hr />
<div><!-- CURATORS: Please replace the {{UnderConstruction}} tag below with {{CuratorApproved}} when the page is ready for wider public consumption --><br />
{{UnderConstruction}}<br />
* [[Author]]: ^^^Tirso Pons^^^ and ^^^Wim Van den Ende^^^<br />
* [[Responsible Curator]]: ^^^Wim Van den Ende^^^<br />
----<br />
<br />
<!-- The data in the table below should be updated by the Author/Curator according to current information on the family --><br />
<div style="float:right"><br />
{| {{Prettytable}} <br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH68'''<br />
|-<br />
|'''Clan''' <br />
|GH-J<br />
|-<br />
|'''Mechanism'''<br />
|retaining<br />
|-<br />
|'''Active site residues'''<br />
|known<br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br />
|-<br />
| colspan="2" |http://www.cazy.org/fam/GH68.html<br />
|}<br />
</div><br />
<!-- This is the end of the table --><br />
<br />
<br />
== Substrate specificities ==<br />
Glycoside hydrolase family GH68 contains enzymes that hydrolyze fructose containing polysaccharides such as levansucrase (sucrose:2,6-β-D-fructan 6-β-D-fructosyltransferase; EC 2.4.1.10); β-fructofuranosidase (EC 3.2.1.26); and inulosucrase (EC 2.4.1.9)<br />
<br />
== Kinetics and Mechanism ==<br />
Family GH68 enzymes are retaining enzymes, as first shown by Koshland and Stein by performing the reaction in <sup>18</sup>O-labeled water and determining the <sup>18</sup>O content of the products <cite>1</cite>. The levansucrases from ''Bacillus subtilis'', ''Gluconacetobacter diazotrophicus'', and ''Streptococcus salivarius'' catalyze transfructosylation via a Ping-Pong mechanism involving the formation of a transient fructosyl-enzyme intermediate<cite>2 3 4 5</cite>. At low sucrose concentrations levansucrase functions as a hydrolase with water as acceptor, whereas at higher substrate concentrations it adds fructosyl units to a variety of acceptors including glucose, fructan and sucrose <cite>2</cite>.<br />
Bacterial levansucrases, whatever their origin, catalyze all these reactions but with different efficiency.<br />
<br />
== Catalytic Residues ==<br />
Retaining glycosidases catalyze hydrolysis in two steps involving a covalent glycosyl enzyme intermediate. The two invariant residues, responsible for the catalytic reaction in family GH68 enzymes, have first been identified experimentally in bacterial levansucrases as an aspartate located close to the N-terminus acting as the catalytic nucleophile and a glutamate acting as the general acid/base <cite>6 7</cite>. In addition, a conserved aspartate residue in the "Arg-Asp-Pro (RDP) motif" stabilize the transition state <cite>5 7 8</cite>.<br />
<br />
== Three-dimensional structures ==<br />
Currently, only two different three dimensional structures of family GH68 enzymes have been solved so far. The first crystal structure was reported for the bacterial levansucrase (SacB) from ''Bacillus subtilis'' subsp. subtilis str. 168 <cite>6</cite>. The second one corresponds to levansucrase (LdsA) from ''Gluconacetobacter diazotrophicus'' SRT4 <cite>9</cite>.<br />
<br />
<br />
== Family Firsts ==<br />
;First stereochemistry determination: ''Bacillus subtilis'' levansucrase <cite>2</cite>.<br />
;First catalytic nucleophile identification: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
;First general acid/base residue identification: ''Zymomonas mobilis'' levansucrase <cite>7</cite>.<br />
;First stabilizing transition-state residue identification: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>8</cite>.<br />
;First prediction of a common beta-propeller catalytic domain in GH68 / clan GH-J: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>10 11</cite>.<br />
;First 3-D structure: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
<br />
== References ==<br />
<biblio><br />
#1 pmid=13174523<br />
#2 pmid=4206083<br />
#3 pmid=814002<br />
#4 pmid=7619044<br />
#5 pmid=10393084<br />
#6 pmid=14517548<br />
#7 pmid=12359071<br />
#8 pmid=9895294<br />
#9 pmid=15869470<br />
#10 pmid=9829697<br />
#11 pmid=11305239<br />
</biblio><br />
<br />
<br />
[[Category:Glycoside Hydrolase Families|GH068]]</div>Tirso Ponshttps://www.cazypedia.org/index.php?title=Glycoside_Hydrolase_Family_68&diff=3918Glycoside Hydrolase Family 682010-02-16T17:14:56Z<p>Tirso Pons: </p>
<hr />
<div><!-- CURATORS: Please replace the {{UnderConstruction}} tag below with {{CuratorApproved}} when the page is ready for wider public consumption --><br />
{{UnderConstruction}}<br />
* [[Author]]: ^^^Tirso Pons^^^ and ^^^Wim Van den Ende^^^<br />
* [[Responsible Curator]]: ^^^Wim Van den Ende^^^<br />
----<br />
<br />
<!-- The data in the table below should be updated by the Author/Curator according to current information on the family --><br />
<div style="float:right"><br />
{| {{Prettytable}} <br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH68'''<br />
|-<br />
|'''Clan''' <br />
|GH-J<br />
|-<br />
|'''Mechanism'''<br />
|retaining<br />
|-<br />
|'''Active site residues'''<br />
|known<br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br />
|-<br />
| colspan="2" |http://www.cazy.org/fam/GH68.html<br />
|}<br />
</div><br />
<!-- This is the end of the table --><br />
<br />
<br />
== Substrate specificities ==<br />
Glycoside hydrolase family GH68 contains enzymes that hydrolyze fructose containing polysaccharides such as levansucrase (sucrose:2,6-β-D-fructan 6-β-D-fructosyltransferase; EC 2.4.1.10); β-fructofuranosidase (EC 3.2.1.26); and inulosucrase (EC 2.4.1.9)<br />
<br />
== Kinetics and Mechanism ==<br />
Family GH68 enzymes are retaining enzymes, as first shown by Koshland and Stein by performing the reaction in <sup>18</sup>O-labeled water and determining the <sup>18</sup>O content of the products <cite>1</cite>. The levansucrases from ''Bacillus subtilis'', ''Gluconacetobacter diazotrophicus'', and ''Streptococcus salivarius'' follows a ping-pong mechanism <cite>2 3 4 5</cite>. At low sucrose concentrations levansucrase functions as a hydrolase with water as acceptor, whereas at higher substrate concentrations it adds fructosyl units to a growing levan chain <cite>2</cite>.<br />
<br />
== Catalytic Residues ==<br />
Retaining glycosidases catalyze hydrolysis in two steps involving a covalent glycosyl enzyme intermediate. The two invariant residues, responsible for the catalytic reaction in family GH68 enzymes, have first been identified experimentally in bacterial levansucrases as an aspartate located close to the N-terminus acting as the catalytic nucleophile and a glutamate acting as the general acid/base <cite>6 7</cite>. In addition, a conserved aspartate residue in the "Arg-Asp-Pro (RDP) motif" stabilize the transition state <cite>5 7 8</cite>.<br />
<br />
== Three-dimensional structures ==<br />
Currently, only two different three dimensional structures of family GH68 enzymes have been solved so far. The first crystal structure was reported for the bacterial levansucrase (SacB) from ''Bacillus subtilis'' subsp. subtilis str. 168 <cite>6</cite>. The second one corresponds to levansucrase (LdsA) from ''Gluconacetobacter diazotrophicus'' SRT4 <cite>9</cite>.<br />
<br />
<br />
== Family Firsts ==<br />
;First stereochemistry determination: ''Bacillus subtilis'' levansucrase <cite>2</cite>.<br />
;First catalytic nucleophile identification: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
;First general acid/base residue identification: ''Zymomonas mobilis'' levansucrase <cite>7</cite>.<br />
;First stabilizing transition-state residue identification: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>8</cite>.<br />
;First prediction of a common beta-propeller catalytic domain in GH68 / clan GH-J: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>10 11</cite>.<br />
;First 3-D structure: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
<br />
== References ==<br />
<biblio><br />
#1 pmid=13174523<br />
#2 pmid=4206083<br />
#3 pmid=814002<br />
#4 pmid=7619044<br />
#5 pmid=10393084<br />
#6 pmid=14517548<br />
#7 pmid=12359071<br />
#8 pmid=9895294<br />
#9 pmid=15869470<br />
#10 pmid=9829697<br />
#11 pmid=11305239<br />
</biblio><br />
<br />
<br />
[[Category:Glycoside Hydrolase Families|GH068]]</div>Tirso Ponshttps://www.cazypedia.org/index.php?title=Glycoside_Hydrolase_Family_68&diff=3917Glycoside Hydrolase Family 682010-02-16T17:12:50Z<p>Tirso Pons: </p>
<hr />
<div><!-- CURATORS: Please replace the {{UnderConstruction}} tag below with {{CuratorApproved}} when the page is ready for wider public consumption --><br />
{{UnderConstruction}}<br />
* [[Author]]: ^^^Tirso Pons^^^ and ^^^Wim Van den Ende^^^<br />
* [[Responsible Curator]]: ^^^Wim Van den Ende^^^<br />
----<br />
<br />
<!-- The data in the table below should be updated by the Author/Curator according to current information on the family --><br />
<div style="float:right"><br />
{| {{Prettytable}} <br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH68'''<br />
|-<br />
|'''Clan''' <br />
|GH-J<br />
|-<br />
|'''Mechanism'''<br />
|retaining<br />
|-<br />
|'''Active site residues'''<br />
|known<br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br />
|-<br />
| colspan="2" |http://www.cazy.org/fam/GH68.html<br />
|}<br />
</div><br />
<!-- This is the end of the table --><br />
<br />
<br />
== Substrate specificities ==<br />
Glycoside hydrolase family GH68 contains enzymes that hydrolyze fructose containing polysaccharides such as levansucrase (sucrose:2,6-β-D-fructan 6-β-D-fructosyltransferase; EC 2.4.1.10); β-fructofuranosidase (EC 3.2.1.26); and inulosucrase (EC 2.4.1.9)<br />
<br />
== Kinetics and Mechanism ==<br />
Family GH68 enzymes are retaining enzymes, as first shown by Koshland and Stein by performing the reaction in <sup>18</sup>O-labeled water and determining the <sup>18</sup>O content of the products <cite>1</cite>. The levansucrases from ''Bacillus subtilis'', ''Gluconacetobacter diazotrophicus'', and ''Streptococcus salivarius'' follows a ping-pong mechanism <cite>2 3 4 5</cite>. At low sucrose concentrations levansucrase functions as a hydrolase with water as acceptor, whereas at higher substrate concentrations it adds fructosyl units to a growing levan chain <cite>2</cite>.<br />
<br />
== Catalytic Residues ==<br />
Retaining glycosidases catalyze hydrolysis in two steps involving a covalent glycosyl enzyme intermediate. The two invariant residues, responsible for the catalytic reaction in family GH68 enzymes, have first been identified experimentally in bacterial levansucrases as an aspartate located close to the N-terminus acting as the catalytic nucleophile and a glutamate acting as the general acid/base <cite>6 7</cite>. In addition, a conserved aspartate residue in the "Arg-Asp-Pro (RDP) motif" stabilize the transition state <cite>5 7 8</cite>.<br />
<br />
== Three-dimensional structures ==<br />
Currently, only two different three dimensional structures of family GH68 enzymes have been solved so far. The first crystal structure was reported for the bacterial levansucrase (SacB) from ''Bacillus subtilis'' subsp. subtilis str. 168 <cite>6</cite>. The second one corresponds to levansucrase (LdsA) from ''Gluconacetobacter diazotrophicus'' SRT4 <cite>9</cite>.<br />
<br />
<br />
== Family Firsts ==<br />
;First stereochemistry determination: ''Bacillus subtilis'' levansucrase <cite>2</cite>.<br />
;First catalytic nucleophile identification: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
;First general acid/base residue identification: ''Zymomonas mobilis'' levansucrase <cite>7</cite>.<br />
;First stabilizing transition-state residue identification: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>8</cite>.<br />
;First prediction of a common beta-propeller catalytic domain in GH68 / GH-J: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>10 11</cite>.<br />
;First 3-D structure: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
<br />
== References ==<br />
<biblio><br />
#1 pmid=13174523<br />
#2 pmid=4206083<br />
#3 pmid=814002<br />
#4 pmid=7619044<br />
#5 pmid=10393084<br />
#6 pmid=14517548<br />
#7 pmid=12359071<br />
#8 pmid=9895294<br />
#9 pmid=15869470<br />
#10 pmid=9829697<br />
#11 pmid=11305239<br />
</biblio><br />
<br />
<br />
[[Category:Glycoside Hydrolase Families|GH068]]</div>Tirso Ponshttps://www.cazypedia.org/index.php?title=Glycoside_Hydrolase_Family_68&diff=3916Glycoside Hydrolase Family 682010-02-16T17:12:18Z<p>Tirso Pons: </p>
<hr />
<div><!-- CURATORS: Please replace the {{UnderConstruction}} tag below with {{CuratorApproved}} when the page is ready for wider public consumption --><br />
{{UnderConstruction}}<br />
* [[Author]]: ^^^Tirso Pons^^^ and ^^^Wim Van den Ende^^^<br />
* [[Responsible Curator]]: ^^^Wim Van den Ende^^^<br />
----<br />
<br />
<!-- The data in the table below should be updated by the Author/Curator according to current information on the family --><br />
<div style="float:right"><br />
{| {{Prettytable}} <br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH68'''<br />
|-<br />
|'''Clan''' <br />
|GH-J<br />
|-<br />
|'''Mechanism'''<br />
|retaining<br />
|-<br />
|'''Active site residues'''<br />
|known<br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br />
|-<br />
| colspan="2" |http://www.cazy.org/fam/GH68.html<br />
|}<br />
</div><br />
<!-- This is the end of the table --><br />
<br />
<br />
== Substrate specificities ==<br />
Glycoside hydrolase family GH68 contains enzymes that hydrolyze fructose containing polysaccharides such as levansucrase (sucrose:2,6-β-D-fructan 6-β-D-fructosyltransferase; EC 2.4.1.10); β-fructofuranosidase (EC 3.2.1.26); and inulosucrase (EC 2.4.1.9)<br />
<br />
== Kinetics and Mechanism ==<br />
Family GH68 enzymes are retaining enzymes, as first shown by Koshland and Stein by performing the reaction in <sup>18</sup>O-labeled water and determining the <sup>18</sup>O content of the products <cite>1</cite>. The levansucrases from ''Bacillus subtilis'', ''Gluconacetobacter diazotrophicus'', and ''Streptococcus salivarius'' follows a ping-pong mechanism <cite>2 3 4 5</cite>. At low sucrose concentrations levansucrase functions as a hydrolase with water as acceptor, whereas at higher substrate concentrations it adds fructosyl units to a growing levan chain <cite>2</cite>.<br />
<br />
== Catalytic Residues ==<br />
Retaining glycosidases catalyze hydrolysis in two steps involving a covalent glycosyl enzyme intermediate. The two invariant residues, responsible for the catalytic reaction in family GH68 enzymes, have first been identified experimentally in bacterial levansucrases as an aspartate located close to the N-terminus acting as the catalytic nucleophile and a glutamate acting as the general acid/base <cite>6 7</cite>. In addition, a conserved aspartate residue in the "Arg-Asp-Pro (RDP) motif" stabilize the transition state <cite>5 7 8</cite>.<br />
<br />
== Three-dimensional structures ==<br />
Currently, only two different three dimensional structures of family GH68 enzymes have been solved so far. The first crystal structure was reported for the bacterial levansucrase (SacB) from ''Bacillus subtilis'' subsp. subtilis str. 168 <cite>6</cite>. The second one corresponds to levansucrase (LdsA) from ''Gluconacetobacter diazotrophicus'' SRT4 <cite>9</cite>.<br />
<br />
<br />
== Family Firsts ==<br />
;First stereochemistry determination: ''Bacillus subtilis'' levansucrase <cite>2</cite>.<br />
;First catalytic nucleophile identification: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
;First general acid/base residue identification: ''Zymomonas mobilis'' levansucrase <cite>7</cite>.<br />
;First stabilizing transition-state residue identification: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>8</cite>.<br />
;First prediction of a common beta-propeller catalytic domain in GH68/GH-J: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>10 11</cite>.<br />
;First 3-D structure: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
<br />
== References ==<br />
<biblio><br />
#1 pmid=13174523<br />
#2 pmid=4206083<br />
#3 pmid=814002<br />
#4 pmid=7619044<br />
#5 pmid=10393084<br />
#6 pmid=14517548<br />
#7 pmid=12359071<br />
#8 pmid=9895294<br />
#9 pmid=15869470<br />
#10 pmid=9829697<br />
#11 pmid=11305239<br />
</biblio><br />
<br />
<br />
[[Category:Glycoside Hydrolase Families|GH068]]</div>Tirso Ponshttps://www.cazypedia.org/index.php?title=Glycoside_Hydrolase_Family_68&diff=3915Glycoside Hydrolase Family 682010-02-16T17:09:51Z<p>Tirso Pons: </p>
<hr />
<div><!-- CURATORS: Please replace the {{UnderConstruction}} tag below with {{CuratorApproved}} when the page is ready for wider public consumption --><br />
{{UnderConstruction}}<br />
* [[Author]]: ^^^Tirso Pons^^^ and ^^^Wim Van den Ende^^^<br />
* [[Responsible Curator]]: ^^^Wim Van den Ende^^^<br />
----<br />
<br />
<!-- The data in the table below should be updated by the Author/Curator according to current information on the family --><br />
<div style="float:right"><br />
{| {{Prettytable}} <br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH68'''<br />
|-<br />
|'''Clan''' <br />
|GH-J<br />
|-<br />
|'''Mechanism'''<br />
|retaining<br />
|-<br />
|'''Active site residues'''<br />
|known<br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br />
|-<br />
| colspan="2" |http://www.cazy.org/fam/GH68.html<br />
|}<br />
</div><br />
<!-- This is the end of the table --><br />
<br />
<br />
== Substrate specificities ==<br />
Glycoside hydrolase family GH68 contains enzymes that hydrolyze fructose containing polysaccharides such as levansucrase (sucrose:2,6-β-D-fructan 6-β-D-fructosyltransferase; EC 2.4.1.10); β-fructofuranosidase (EC 3.2.1.26); and inulosucrase (EC 2.4.1.9)<br />
<br />
== Kinetics and Mechanism ==<br />
Family GH68 enzymes are retaining enzymes, as first shown by Koshland and Stein by performing the reaction in <sup>18</sup>O-labeled water and determining the <sup>18</sup>O content of the products <cite>1</cite>. The levansucrases from ''Bacillus subtilis'', ''Gluconacetobacter diazotrophicus'', and ''Streptococcus salivarius'' follows a ping-pong mechanism <cite>2 3 4 5</cite>. At low sucrose concentrations levansucrase functions as a hydrolase with water as acceptor, whereas at higher substrate concentrations it adds fructosyl units to a growing levan chain <cite>2</cite>.<br />
<br />
== Catalytic Residues ==<br />
Retaining glycosidases catalyze hydrolysis in two steps involving a covalent glycosyl enzyme intermediate. The two invariant residues, responsible for the catalytic reaction in family GH68 enzymes, have first been identified experimentally in bacterial levansucrases as an aspartate located close to the N-terminus acting as the catalytic nucleophile and a glutamate acting as the general acid/base <cite>6 7</cite>. In addition, a conserved aspartate residue in the "Arg-Asp-Pro (RDP) motif" stabilize the transition state <cite>5 7 8</cite>.<br />
<br />
== Three-dimensional structures ==<br />
Currently, only two different three dimensional structures of family GH68 enzymes have been solved so far. The first crystal structure was reported for the bacterial levansucrase (SacB) from ''Bacillus subtilis'' subsp. subtilis str. 168 <cite>6</cite>. The second one corresponds to levansucrase (LdsA) from ''Gluconacetobacter diazotrophicus'' SRT4 <cite>9</cite>.<br />
<br />
<br />
== Family Firsts ==<br />
;First stereochemistry determination: ''Bacillus subtilis'' levansucrase <cite>2</cite>.<br />
;First catalytic nucleophile identification: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
;First general acid/base residue identification: ''Zymomonas mobilis'' levansucrase <cite>7</cite>.<br />
;First stabilizing transition-state residue identification: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>8</cite>.<br />
;First prediction of a common beta-propeller catalytic domain in GH68: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>10 11</cite>.<br />
;First 3-D structure: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
<br />
== References ==<br />
<biblio><br />
#1 pmid=13174523<br />
#2 pmid=4206083<br />
#3 pmid=814002<br />
#4 pmid=7619044<br />
#5 pmid=10393084<br />
#6 pmid=14517548<br />
#7 pmid=12359071<br />
#8 pmid=9895294<br />
#9 pmid=15869470<br />
#10 pmid=9829697<br />
#11 pmid=11305239<br />
</biblio><br />
<br />
<br />
[[Category:Glycoside Hydrolase Families|GH068]]</div>Tirso Ponshttps://www.cazypedia.org/index.php?title=Glycoside_Hydrolase_Family_68&diff=3914Glycoside Hydrolase Family 682010-02-16T17:07:12Z<p>Tirso Pons: </p>
<hr />
<div><!-- CURATORS: Please replace the {{UnderConstruction}} tag below with {{CuratorApproved}} when the page is ready for wider public consumption --><br />
{{UnderConstruction}}<br />
* [[Author]]: ^^^Tirso Pons^^^ and ^^^Wim Van den Ende^^^<br />
* [[Responsible Curator]]: ^^^Wim Van den Ende^^^<br />
----<br />
<br />
<!-- The data in the table below should be updated by the Author/Curator according to current information on the family --><br />
<div style="float:right"><br />
{| {{Prettytable}} <br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH68'''<br />
|-<br />
|'''Clan''' <br />
|GH-J<br />
|-<br />
|'''Mechanism'''<br />
|retaining<br />
|-<br />
|'''Active site residues'''<br />
|known<br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br />
|-<br />
| colspan="2" |http://www.cazy.org/fam/GH68.html<br />
|}<br />
</div><br />
<!-- This is the end of the table --><br />
<br />
<br />
== Substrate specificities ==<br />
Glycoside hydrolase family GH68 contains enzymes that hydrolyze fructose containing polysaccharides such as levansucrase (sucrose:2,6-β-D-fructan 6-β-D-fructosyltransferase; EC 2.4.1.10); β-fructofuranosidase (EC 3.2.1.26); and inulosucrase (EC 2.4.1.9)<br />
<br />
== Kinetics and Mechanism ==<br />
Family GH68 enzymes are retaining enzymes, as first shown by Koshland and Stein by performing the reaction in <sup>18</sup>O-labeled water and determining the <sup>18</sup>O content of the products <cite>1</cite>. The levansucrases from ''Bacillus subtilis'', ''Gluconacetobacter diazotrophicus'', and ''Streptococcus salivarius'' follows a ping-pong mechanism <cite>2 3 4 5</cite>. At low sucrose concentrations levansucrase functions as a hydrolase with water as acceptor, whereas at higher substrate concentrations it adds fructosyl units to a growing levan chain <cite>2</cite>.<br />
<br />
== Catalytic Residues ==<br />
Retaining glycosidases catalyze hydrolysis in two steps involving a covalent glycosyl enzyme intermediate. The two invariant residues, responsible for the catalytic reaction in family GH68 enzymes, have first been identified experimentally in bacterial levansucrases as an aspartate located close to the N-terminus acting as the catalytic nucleophile and a glutamate acting as the general acid/base <cite>6 7</cite>. In addition, a conserved aspartate residue in the "Arg-Asp-Pro (RDP) motif" stabilize the transition state <cite>5 7 8</cite>.<br />
<br />
== Three-dimensional structures ==<br />
Currently, only two different three dimensional structures of family GH68 enzymes have been solved so far. The first crystal structure was reported for the bacterial levansucrase (SacB) from ''Bacillus subtilis'' subsp. subtilis str. 168 <cite>6</cite>. The second one corresponds to levansucrase (LdsA) from ''Gluconacetobacter diazotrophicus'' SRT4 <cite>9</cite>.<br />
<br />
<br />
== Family Firsts ==<br />
;First stereochemistry determination: ''Bacillus subtilis'' levansucrase <cite></cite>.<br />
;First catalytic nucleophile identification: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
;First general acid/base residue identification: ''Zymomonas mobilis'' levansucrase <cite>7</cite>.<br />
;First stabilizing transition-state residue identification: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>8</cite>.<br />
;First prediction of a common beta-propeller catalytic domain in GH68: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>10 11</cite>.<br />
;First 3-D structure: ''Bacillus subtilis'' levansucrase <cite>6</cite>.<br />
<br />
== References ==<br />
<biblio><br />
#1 pmid=13174523<br />
#2 pmid=4206083<br />
#3 pmid=814002<br />
#4 pmid=7619044<br />
#5 pmid=10393084<br />
#6 pmid=14517548<br />
#7 pmid=12359071<br />
#8 pmid=9895294<br />
#9 pmid=15869470<br />
#10 pmid=11305239<br />
#11 pmid=9829697<br />
</biblio><br />
<br />
<br />
[[Category:Glycoside Hydrolase Families|GH068]]</div>Tirso Ponshttps://www.cazypedia.org/index.php?title=Glycoside_Hydrolase_Family_68&diff=3897Glycoside Hydrolase Family 682010-02-16T16:28:37Z<p>Tirso Pons: </p>
<hr />
<div><!-- CURATORS: Please replace the {{UnderConstruction}} tag below with {{CuratorApproved}} when the page is ready for wider public consumption --><br />
{{UnderConstruction}}<br />
* [[Author]]: ^^^Tirso Pons^^^ and ^^^Wim Van den Ende^^^<br />
* [[Responsible Curator]]: ^^^Wim Van den Ende^^^<br />
----<br />
<br />
<!-- The data in the table below should be updated by the Author/Curator according to current information on the family --><br />
<div style="float:right"><br />
{| {{Prettytable}} <br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH68'''<br />
|-<br />
|'''Clan''' <br />
|GH-J<br />
|-<br />
|'''Mechanism'''<br />
|retaining<br />
|-<br />
|'''Active site residues'''<br />
|known<br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br />
|-<br />
| colspan="2" |http://www.cazy.org/fam/GH68.html<br />
|}<br />
</div><br />
<!-- This is the end of the table --><br />
<br />
<br />
== Substrate specificities ==<br />
Glycoside hydrolase family GH68 contains enzymes that hydrolyze fructose containing polysaccharides such as levansucrase (sucrose:2,6-β-D-fructan 6-β-D-fructosyltransferase; EC 2.4.1.10); β-fructofuranosidase (EC 3.2.1.26); and inulosucrase (EC 2.4.1.9)<br />
<br />
== Kinetics and Mechanism ==<br />
Family GH68 enzymes are retaining enzymes, as first shown by Koshland and Stein by performing the reaction in <sup>18</sup>O-labeled water and determining the <sup>18</sup>O content of the products <cite>1</cite>. The levansucrases from ''Bacillus subtilis'', ''Gluconacetobacter diazotrophicus'', and ''Streptococcus salivarius'' follows a ping-pong mechanism <cite>2 3 4 5</cite>. At low sucrose concentrations levansucrase functions as a hydrolase with water as acceptor, whereas at higher substrate concentrations it adds fructosyl units to a growing levan chain <cite>2</cite>.<br />
<br />
== Catalytic Residues ==<br />
Retaining glycosidases catalyze hydrolysis in two steps involving a covalent glycosyl enzyme intermediate. The two invariant residues, responsible for the catalytic reaction in family GH68 enzymes, have first been identified experimentally in bacterial levansucrases as an aspartate located close to the N-terminus acting as the catalytic nucleophile and a glutamate acting as the general acid/base <cite>6 7</cite>. In addition, a conserved aspartate residue in the "Arg-Asp-Pro (RDP) motif" stabilize the transition state <cite>5 7 8</cite>.<br />
<br />
== Three-dimensional structures ==<br />
Currently, only two different three dimensional structures of family GH68 enzymes have been solved so far. The first crystal structure was reported for the bacterial levansucrase (SacB) from ''Bacillus subtilis'' subsp. subtilis str. 168 <cite>6</cite>. The second one corresponds to levansucrase (LdsA) from ''Gluconacetobacter diazotrophicus'' SRT4 <cite>9</cite>.<br />
<br />
<br />
== Family Firsts ==<br />
;First stereochemistry determination: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite></cite>.<br />
;First catalytic nucleophile identification: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite></cite>.<br />
;First general acid/base residue identification: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite></cite>.<br />
;First 3-D structure: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite></cite>.<br />
<br />
== References ==<br />
<biblio><br />
#1 pmid=13174523<br />
#2 pmid=4206083<br />
#3 pmid=814002<br />
#4 pmid=7619044<br />
#5 pmid=10393084<br />
#6 pmid=14517548<br />
#7 pmid=12359071<br />
#8 pmid=9895294<br />
#9 pmid=15869470<br />
</biblio><br />
<br />
<br />
[[Category:Glycoside Hydrolase Families|GH068]]</div>Tirso Ponshttps://www.cazypedia.org/index.php?title=Glycoside_Hydrolase_Family_68&diff=3896Glycoside Hydrolase Family 682010-02-16T16:26:43Z<p>Tirso Pons: </p>
<hr />
<div><!-- CURATORS: Please replace the {{UnderConstruction}} tag below with {{CuratorApproved}} when the page is ready for wider public consumption --><br />
{{UnderConstruction}}<br />
* [[Author]]: ^^^Tirso Pons^^^ and ^^^Wim Van den Ende^^^<br />
* [[Responsible Curator]]: ^^^Wim Van den Ende^^^<br />
----<br />
<br />
<!-- The data in the table below should be updated by the Author/Curator according to current information on the family --><br />
<div style="float:right"><br />
{| {{Prettytable}} <br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH68'''<br />
|-<br />
|'''Clan''' <br />
|GH-J<br />
|-<br />
|'''Mechanism'''<br />
|retaining<br />
|-<br />
|'''Active site residues'''<br />
|known<br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br />
|-<br />
| colspan="2" |http://www.cazy.org/fam/GH68.html<br />
|}<br />
</div><br />
<!-- This is the end of the table --><br />
<br />
<br />
== Substrate specificities ==<br />
Glycoside hydrolase family GH68 contains enzymes that hydrolyze fructose containing polysaccharides such as levansucrase (sucrose:2,6-β-D-fructan 6-β-D-fructosyltransferase; EC 2.4.1.10); β-fructofuranosidase (EC 3.2.1.26); and inulosucrase (EC 2.4.1.9)<br />
<br />
== Kinetics and Mechanism ==<br />
Family GH68 enzymes are retaining enzymes, as first shown by Koshland and Stein by performing the reaction in <sup>18</sup>O-labeled water and determining the <sup>18</sup>O content of the products <cite>1</cite>. The levansucrases from ''Bacillus subtilis'', ''Gluconacetobacter diazotrophicus'', and ''Streptococcus salivarius'' follows a ping-pong mechanism <cite>2 3 4 5</cite>. At low sucrose concentrations levansucrase functions as a hydrolase with water as acceptor, whereas at higher substrate concentrations it adds fructosyl units to a growing levan chain <cite>2</cite>.<br />
<br />
== Catalytic Residues ==<br />
Retaining glycosidases catalyze hydrolysis in two steps involving a covalent glycosyl enzyme intermediate. The two invariant residues, responsible for the catalytic reaction in family GH68 enzymes, have first been identified experimentally in bacterial levansucrases as an aspartate located close to the N-terminus acting as the catalytic nucleophile and a glutamate acting as the general acid/base <cite>6 7</cite>. In addition, a conserved aspartate residue in the "Arg-Asp-Pro (RDP) motif" stabilize the transition state <cite>5 7 8</cite>.<br />
<br />
== Three-dimensional structures ==<br />
Currently, only two different three dimensional structures of family GH68 enzymes have been solved so far. The first crystal structure was reported for the bacterial levansucrase (SacB) from ''Bacillus subtilis'' subsp. subtilis str. 168 <cite>6</cite>. The second one corresponds to levansucrase (LdsA) from ''Gluconacetobacter diazotrophicus'' SRT4 <cite>9</cite>.<br />
<br />
<br />
== Family Firsts ==<br />
;First stereochemistry determination: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite></cite>.<br />
;First catalytic nucleophile identification: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite></cite>.<br />
;First general acid/base residue identification: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite></cite>.<br />
;First 3-D structure: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite></cite>.<br />
<br />
== References ==<br />
<biblio><br />
#1 pmid=13174523<br />
#2 pmid=4206083<br />
#3 pmid=814002<br />
#4 pmid=7619044<br />
#5 pmid=10393084<br />
#6 pmid=14517548<br />
#7 pmid=12359071<br />
#8 pmid=9895294<br />
#9 pmid=15869470<br />
#X4 isbn=978-0-240-52118-3<br />
#MikesClassic Sinnott, M.L. (1990) Catalytic mechanisms of enzymic glycosyl transfer. Chem. Rev. 90, 1171-1202. [http://dx.doi.org/10.1021/cr00105a006 DOI: 10.1021/cr00105a006]<br />
<br />
</biblio><br />
<br />
<br />
[[Category:Glycoside Hydrolase Families|GH068]]</div>Tirso Ponshttps://www.cazypedia.org/index.php?title=Glycoside_Hydrolase_Family_68&diff=3895Glycoside Hydrolase Family 682010-02-16T16:20:03Z<p>Tirso Pons: </p>
<hr />
<div><!-- CURATORS: Please replace the {{UnderConstruction}} tag below with {{CuratorApproved}} when the page is ready for wider public consumption --><br />
{{UnderConstruction}}<br />
* [[Author]]: ^^^Tirso Pons^^^ and ^^^Wim Van den Ende^^^<br />
* [[Responsible Curator]]: ^^^Wim Van den Ende^^^<br />
----<br />
<br />
<!-- The data in the table below should be updated by the Author/Curator according to current information on the family --><br />
<div style="float:right"><br />
{| {{Prettytable}} <br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH68'''<br />
|-<br />
|'''Clan''' <br />
|GH-J<br />
|-<br />
|'''Mechanism'''<br />
|retaining<br />
|-<br />
|'''Active site residues'''<br />
|known<br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br />
|-<br />
| colspan="2" |http://www.cazy.org/fam/GH68.html<br />
|}<br />
</div><br />
<!-- This is the end of the table --><br />
<br />
<br />
== Substrate specificities ==<br />
Glycoside hydrolase family GH68 contains enzymes that hydrolyze fructose containing polysaccharides such as levansucrase (sucrose:2,6-β-D-fructan 6-β-D-fructosyltransferase; EC 2.4.1.10); β-fructofuranosidase (EC 3.2.1.26); and inulosucrase (EC 2.4.1.9)<br />
<br />
== Kinetics and Mechanism ==<br />
Family GH68 enzymes are retaining enzymes, as first shown by Koshland and Stein by performing the reaction in <sup>18</sup>O-labeled water and determining the <sup>18</sup>O content of the products <cite>1</cite>. The levansucrases from ''Bacillus subtilis'', ''Gluconacetobacter diazotrophicus'', and ''Streptococcus salivarius'' follows a ping-pong mechanism <cite>2 3 4 5</cite>. At low sucrose concentrations levansucrase functions as a hydrolase with water as acceptor, whereas at higher substrate concentrations it adds fructosyl units to a growing levan chain <cite>2</cite>.<br />
<br />
== Catalytic Residues ==<br />
Retaining glycosidases catalyze hydrolysis in two steps involving a covalent glycosyl enzyme intermediate. The two invariant residues, responsible for the catalytic reaction in family GH68 enzymes, have first been identified experimentally in bacterial levansucrases as an aspartate located close to the N-terminus acting as the catalytic nucleophile and a glutamate acting as the general acid/base <cite>6 7</cite>. In addition, a conserved aspartate residue in the "Arg-Asp-Pro (RDP) motif" stabilize the transition state <cite>7</cite>.<br />
<br />
== Three-dimensional structures ==<br />
Currently, only two different three dimensional structures of family GH68 enzymes have been solved so far. The first crystal structure was reported for the bacterial levansucrase (SacB) from ''Bacillus subtilis'' subsp. subtilis str. 168 <cite>6</cite>. The second one corresponds to levansucrase (LdsA) from ''Gluconacetobacter diazotrophicus'' SRT4 <cite>X3</cite>.<br />
<br />
<br />
== Family Firsts ==<br />
;First stereochemistry determination: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite>1</cite>.<br />
;First catalytic nucleophile identification: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite>MikesClassic</cite>.<br />
;First general acid/base residue identification: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite>He1999</cite>.<br />
;First 3-D structure: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite>3</cite>.<br />
<br />
== References ==<br />
You can even cite books using just the ISBN <cite>X4</cite>. References that are not in PubMed can be typed in by hand <cite>MikesClassic</cite>. <br />
<br />
<biblio><br />
#1 pmid=13174523<br />
#2 pmid=4206083<br />
#3 pmid=814002<br />
#4 pmid=7619044<br />
#5 pmid=10393084<br />
#6 pmid=14517548<br />
#7 pmid=12359071<br />
#X3 pmid=15869470<br />
#X4 isbn=978-0-240-52118-3<br />
#MikesClassic Sinnott, M.L. (1990) Catalytic mechanisms of enzymic glycosyl transfer. Chem. Rev. 90, 1171-1202. [http://dx.doi.org/10.1021/cr00105a006 DOI: 10.1021/cr00105a006]<br />
<br />
</biblio><br />
<br />
<br />
[[Category:Glycoside Hydrolase Families|GH068]]</div>Tirso Ponshttps://www.cazypedia.org/index.php?title=Glycoside_Hydrolase_Family_68&diff=3891Glycoside Hydrolase Family 682010-02-16T15:52:12Z<p>Tirso Pons: </p>
<hr />
<div><!-- CURATORS: Please replace the {{UnderConstruction}} tag below with {{CuratorApproved}} when the page is ready for wider public consumption --><br />
{{UnderConstruction}}<br />
* [[Author]]: ^^^Tirso Pons^^^ and ^^^Wim Van den Ende^^^<br />
* [[Responsible Curator]]: ^^^Wim Van den Ende^^^<br />
----<br />
<br />
<!-- The data in the table below should be updated by the Author/Curator according to current information on the family --><br />
<div style="float:right"><br />
{| {{Prettytable}} <br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH68'''<br />
|-<br />
|'''Clan''' <br />
|GH-J<br />
|-<br />
|'''Mechanism'''<br />
|retaining<br />
|-<br />
|'''Active site residues'''<br />
|known<br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br />
|-<br />
| colspan="2" |http://www.cazy.org/fam/GH68.html<br />
|}<br />
</div><br />
<!-- This is the end of the table --><br />
<br />
<br />
== Substrate specificities ==<br />
Glycoside hydrolase family GH68 contains enzymes that hydrolyze fructose containing polysaccharides such as levansucrase (sucrose:2,6-β-D-fructan 6-β-D-fructosyltransferase; EC 2.4.1.10); β-fructofuranosidase (EC 3.2.1.26); and inulosucrase (EC 2.4.1.9)<br />
<br />
== Kinetics and Mechanism ==<br />
Family GH68 enzymes are retaining enzymes, as first shown by Koshland and Stein by performing the reaction in <sup>18</sup>O-labeled water and determining the <sup>18</sup>O content of the products <cite>1</cite>. The levansucrases from ''Bacillus subtilis'', ''Gluconacetobacter diazotrophicus'', and ''Streptococcus salivarius'' follows a ping-pong mechanism <cite>2 3 4 5</cite>. At low sucrose concentrations levansucrase functions as a hydrolase with water as acceptor, whereas at higher substrate concentrations it adds fructosyl units to a growing levan chain.<br />
<br />
== Catalytic Residues ==<br />
Retaining glycosidases catalyze hydrolysis in two steps involving a covalent glycosyl enzyme intermediate. The two invariant residues, responsible for the catalytic reaction in family GH32 enzymes, have first been identified experimentally in yeast invertase as an aspartate located close to the N-terminus acting as the catalytic nucleophile and a glutamate acting as the general acid/base.<br />
<br />
== Three-dimensional structures ==<br />
Currently, only two different three dimensional structures of family GH68 enzymes have been solved so far. The first crystal structure was reported for the bacterial levansucrase (SacB) from ''Bacillus subtilis'' subsp. subtilis str. 168 <cite>X2</cite>. The second one corresponds to levansucrase (LdsA) from ''Gluconacetobacter diazotrophicus'' SRT4 <cite>X3</cite>.<br />
<br />
<br />
== Family Firsts ==<br />
;First stereochemistry determination: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite>1</cite>.<br />
;First catalytic nucleophile identification: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite>MikesClassic</cite>.<br />
;First general acid/base residue identification: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite>He1999</cite>.<br />
;First 3-D structure: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite>3</cite>.<br />
<br />
== References ==<br />
You can even cite books using just the ISBN <cite>X4</cite>. References that are not in PubMed can be typed in by hand <cite>MikesClassic</cite>. <br />
<br />
<biblio><br />
#1 pmid=13174523<br />
#2 pmid=4206083<br />
#3 pmid=814002<br />
#4 pmid=7619044<br />
#5 pmid=10393084<br />
<br />
#X2 pmid=14517548<br />
#X3 pmid=15869470<br />
#X4 isbn=978-0-240-52118-3<br />
#MikesClassic Sinnott, M.L. (1990) Catalytic mechanisms of enzymic glycosyl transfer. Chem. Rev. 90, 1171-1202. [http://dx.doi.org/10.1021/cr00105a006 DOI: 10.1021/cr00105a006]<br />
<br />
</biblio><br />
<br />
<br />
[[Category:Glycoside Hydrolase Families|GH068]]</div>Tirso Ponshttps://www.cazypedia.org/index.php?title=Glycoside_Hydrolase_Family_68&diff=3863Glycoside Hydrolase Family 682010-02-16T11:45:50Z<p>Tirso Pons: </p>
<hr />
<div><!-- CURATORS: Please replace the {{UnderConstruction}} tag below with {{CuratorApproved}} when the page is ready for wider public consumption --><br />
{{UnderConstruction}}<br />
* [[Author]]: ^^^Tirso Pons^^^ and ^^^Wim Van den Ende^^^<br />
* [[Responsible Curator]]: ^^^Wim Van den Ende^^^<br />
----<br />
<br />
<!-- The data in the table below should be updated by the Author/Curator according to current information on the family --><br />
<div style="float:right"><br />
{| {{Prettytable}} <br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH68'''<br />
|-<br />
|'''Clan''' <br />
|GH-J<br />
|-<br />
|'''Mechanism'''<br />
|retaining<br />
|-<br />
|'''Active site residues'''<br />
|known<br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br />
|-<br />
| colspan="2" |http://www.cazy.org/fam/GH68.html<br />
|}<br />
</div><br />
<!-- This is the end of the table --><br />
<br />
<br />
== Substrate specificities ==<br />
Glycoside hydrolase family GH68 contains enzymes that hydrolyze fructose containing polysaccharides such as levansucrase (EC 2.4.1.10); β-fructofuranosidase (EC 3.2.1.26); and inulosucrase (EC 2.4.1.9)<br />
<br />
== Kinetics and Mechanism ==<br />
Family GH68 enzymes are retaining enzymes, as first shown by Koshland and Stein by performing the reaction in <sup>18</sup>O-labeled water and determining the <sup>18</sup>O content of the products <cite>1</cite>.<br />
<br />
== Catalytic Residues ==<br />
Content is to be added here.<br />
<br />
<br />
== Three-dimensional structures ==<br />
Currently, only two different three dimensional structures of family GH68 enzymes have been solved so far. The first crystal structure was reported for the bacterial levansucrase (SacB) from Bacillus subtilis subsp. subtilis str. 168 <cite>2</cite>. The second one corresponds to levansucrase (LdsA) from Gluconacetobacter diazotrophicus SRT4 <cite>3</cite>.<br />
<br />
<br />
== Family Firsts ==<br />
;First stereochemistry determination: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite>1</cite>.<br />
;First catalytic nucleophile identification: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite>MikesClassic</cite>.<br />
;First general acid/base residue identification: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite>He1999</cite>.<br />
;First 3-D structure: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite>3</cite>.<br />
<br />
== References ==<br />
You can even cite books using just the ISBN <cite>X3</cite>. References that are not in PubMed can be typed in by hand <cite>MikesClassic</cite>. <br />
<br />
<biblio><br />
#1 pmid=13174523<br />
#2 pmid=14517548<br />
#3 pmid=15869470<br />
#X3 isbn=978-0-240-52118-3<br />
#MikesClassic Sinnott, M.L. (1990) Catalytic mechanisms of enzymic glycosyl transfer. Chem. Rev. 90, 1171-1202. [http://dx.doi.org/10.1021/cr00105a006 DOI: 10.1021/cr00105a006]<br />
<br />
</biblio><br />
<br />
<br />
[[Category:Glycoside Hydrolase Families|GH068]]</div>Tirso Ponshttps://www.cazypedia.org/index.php?title=Glycoside_Hydrolase_Family_68&diff=3862Glycoside Hydrolase Family 682010-02-16T11:41:32Z<p>Tirso Pons: </p>
<hr />
<div><!-- CURATORS: Please replace the {{UnderConstruction}} tag below with {{CuratorApproved}} when the page is ready for wider public consumption --><br />
{{UnderConstruction}}<br />
* [[Author]]: ^^^Tirso Pons^^^ and ^^^Wim Van den Ende^^^<br />
* [[Responsible Curator]]: ^^^Wim Van den Ende^^^<br />
----<br />
<br />
<!-- The data in the table below should be updated by the Author/Curator according to current information on the family --><br />
<div style="float:right"><br />
{| {{Prettytable}} <br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH68'''<br />
|-<br />
|'''Clan''' <br />
|GH-J<br />
|-<br />
|'''Mechanism'''<br />
|retaining<br />
|-<br />
|'''Active site residues'''<br />
|known<br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br />
|-<br />
| colspan="2" |http://www.cazy.org/fam/GH68.html<br />
|}<br />
</div><br />
<!-- This is the end of the table --><br />
<br />
<br />
== Substrate specificities ==<br />
Glycoside hydrolase family GH68 contains enzymes that hydrolyze fructose containing polysaccharides such as levansucrase (EC 2.4.1.10); β-fructofuranosidase (EC 3.2.1.26); and inulosucrase (EC 2.4.1.9)<br />
<br />
== Kinetics and Mechanism ==<br />
Family GH68 enzymes are retaining enzymes, as first shown by Koshland and Stein by performing the reaction in 18O-labeled water and determining the 18O content of the products <cite>1</cite>.<br />
<br />
<br />
== Catalytic Residues ==<br />
Content is to be added here.<br />
<br />
<br />
== Three-dimensional structures ==<br />
Currently, only two different three dimensional structures of family GH68 enzymes have been solved so far. The first crystal structure was reported for the bacterial levansucrase (SacB) from Bacillus subtilis subsp. subtilis str. 168 <cite>2</cite>. The second one corresponds to levansucrase (LdsA) from Gluconacetobacter diazotrophicus SRT4 <cite>3</cite>.<br />
<br />
<br />
== Family Firsts ==<br />
;First stereochemistry determination: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite>Comfort2007</cite>.<br />
;First catalytic nucleophile identification: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite>MikesClassic</cite>.<br />
;First general acid/base residue identification: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite>He1999</cite>.<br />
;First 3-D structure: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite>3</cite>.<br />
<br />
== References ==<br />
You can even cite books using just the ISBN <cite>X3</cite>. References that are not in PubMed can be typed in by hand <cite>MikesClassic</cite>. <br />
<br />
<biblio><br />
#1 pmid=13174523<br />
#2 pmid=14517548<br />
#3 pmid=15869470<br />
#X3 isbn=978-0-240-52118-3<br />
#MikesClassic Sinnott, M.L. (1990) Catalytic mechanisms of enzymic glycosyl transfer. Chem. Rev. 90, 1171-1202. [http://dx.doi.org/10.1021/cr00105a006 DOI: 10.1021/cr00105a006]<br />
<br />
</biblio><br />
<br />
<br />
[[Category:Glycoside Hydrolase Families|GH068]]</div>Tirso Ponshttps://www.cazypedia.org/index.php?title=Glycoside_Hydrolase_Family_68&diff=3861Glycoside Hydrolase Family 682010-02-16T11:39:53Z<p>Tirso Pons: </p>
<hr />
<div><!-- CURATORS: Please replace the {{UnderConstruction}} tag below with {{CuratorApproved}} when the page is ready for wider public consumption --><br />
{{UnderConstruction}}<br />
* [[Author]]: ^^^Tirso Pons^^^ and ^^^Wim Van den Ende^^^<br />
* [[Responsible Curator]]: ^^^Wim Van den Ende^^^<br />
----<br />
<br />
<!-- The data in the table below should be updated by the Author/Curator according to current information on the family --><br />
<div style="float:right"><br />
{| {{Prettytable}} <br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH68'''<br />
|-<br />
|'''Clan''' <br />
|GH-J<br />
|-<br />
|'''Mechanism'''<br />
|retaining<br />
|-<br />
|'''Active site residues'''<br />
|known<br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br />
|-<br />
| colspan="2" |http://www.cazy.org/fam/GH68.html<br />
|}<br />
</div><br />
<!-- This is the end of the table --><br />
<br />
<br />
== Substrate specificities ==<br />
Glycoside hydrolase family GH68 contains enzymes that hydrolyze fructose containing polysaccharides such as levansucrase (EC 2.4.1.10); β-fructofuranosidase (EC 3.2.1.26); and inulosucrase (EC 2.4.1.9)<br />
<br />
== Kinetics and Mechanism ==<br />
Family GH68 enzymes are retaining enzymes, as first shown by Koshland and Stein by performing the reaction in 18O-labeled water and determining the 18O content of the products <cite>1</cite>.<br />
<br />
<br />
== Catalytic Residues ==<br />
Content is to be added here.<br />
<br />
<br />
== Three-dimensional structures ==<br />
Currently, only two different three dimensional structures of family GH68 enzymes have been solved so far. The first crystal structure was reported for the bacterial levansucrase (SacB) from Bacillus subtilis subsp. subtilis str. 168 <cite>X1</cite>. The second one corresponds to levansucrase (LdsA) from Gluconacetobacter diazotrophicus SRT4 <cite>X2</cite>.<br />
<br />
<br />
== Family Firsts ==<br />
;First stereochemistry determination: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite>Comfort2007</cite>.<br />
;First catalytic nucleophile identification: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite>MikesClassic</cite>.<br />
;First general acid/base residue identification: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite>He1999</cite>.<br />
;First 3-D structure: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite>3</cite>.<br />
<br />
== References ==<br />
You can even cite books using just the ISBN <cite>3</cite>. References that are not in PubMed can be typed in by hand <cite>MikesClassic</cite>. <br />
<br />
<biblio><br />
#1 pmid=13174523<br />
#X1 pmid=14517548<br />
#X2 pmid=15869470<br />
#3 isbn=978-0-240-52118-3<br />
#MikesClassic Sinnott, M.L. (1990) Catalytic mechanisms of enzymic glycosyl transfer. Chem. Rev. 90, 1171-1202. [http://dx.doi.org/10.1021/cr00105a006 DOI: 10.1021/cr00105a006]<br />
<br />
</biblio><br />
<br />
<br />
[[Category:Glycoside Hydrolase Families|GH068]]</div>Tirso Ponshttps://www.cazypedia.org/index.php?title=Glycoside_Hydrolase_Family_68&diff=3860Glycoside Hydrolase Family 682010-02-16T11:35:34Z<p>Tirso Pons: </p>
<hr />
<div><!-- CURATORS: Please replace the {{UnderConstruction}} tag below with {{CuratorApproved}} when the page is ready for wider public consumption --><br />
{{UnderConstruction}}<br />
* [[Author]]: ^^^Tirso Pons^^^ and ^^^Wim Van den Ende^^^<br />
* [[Responsible Curator]]: ^^^Wim Van den Ende^^^<br />
----<br />
<br />
<!-- The data in the table below should be updated by the Author/Curator according to current information on the family --><br />
<div style="float:right"><br />
{| {{Prettytable}} <br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH68'''<br />
|-<br />
|'''Clan''' <br />
|GH-J<br />
|-<br />
|'''Mechanism'''<br />
|retaining<br />
|-<br />
|'''Active site residues'''<br />
|known<br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br />
|-<br />
| colspan="2" |http://www.cazy.org/fam/GH68.html<br />
|}<br />
</div><br />
<!-- This is the end of the table --><br />
<br />
<br />
== Substrate specificities ==<br />
Glycoside hydrolase family GH68 contains enzymes that hydrolyze fructose containing polysaccharides such as levansucrase (EC 2.4.1.10); β-fructofuranosidase (EC 3.2.1.26); and inulosucrase (EC 2.4.1.9)<br />
<br />
== Kinetics and Mechanism ==<br />
Content is to be added here.<br />
<br />
<br />
== Catalytic Residues ==<br />
Content is to be added here.<br />
<br />
<br />
== Three-dimensional structures ==<br />
Currently, only two different three dimensional structures of family GH68 enzymes have been solved so far. The first crystal structure was reported for the bacterial levansucrase (SacB) from Bacillus subtilis subsp. subtilis str. 168 <cite>X1</cite>. The second one corresponds to levansucrase (LdsA) from Gluconacetobacter diazotrophicus SRT4 <cite>X2</cite>.<br />
<br />
<br />
== Family Firsts ==<br />
;First stereochemistry determination: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite>Comfort2007</cite>.<br />
;First catalytic nucleophile identification: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite>MikesClassic</cite>.<br />
;First general acid/base residue identification: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite>He1999</cite>.<br />
;First 3-D structure: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite>3</cite>.<br />
<br />
== References ==<br />
You can even cite books using just the ISBN <cite>3</cite>. References that are not in PubMed can be typed in by hand <cite>MikesClassic</cite>. <br />
<br />
<biblio><br />
#X1 pmid=14517548<br />
#X2 pmid=15869470<br />
#3 isbn=978-0-240-52118-3<br />
#MikesClassic Sinnott, M.L. (1990) Catalytic mechanisms of enzymic glycosyl transfer. Chem. Rev. 90, 1171-1202. [http://dx.doi.org/10.1021/cr00105a006 DOI: 10.1021/cr00105a006]<br />
<br />
</biblio><br />
<br />
<br />
[[Category:Glycoside Hydrolase Families|GH068]]</div>Tirso Ponshttps://www.cazypedia.org/index.php?title=Glycoside_Hydrolase_Family_68&diff=3859Glycoside Hydrolase Family 682010-02-16T11:34:01Z<p>Tirso Pons: </p>
<hr />
<div><!-- CURATORS: Please replace the {{UnderConstruction}} tag below with {{CuratorApproved}} when the page is ready for wider public consumption --><br />
{{UnderConstruction}}<br />
* [[Author]]: ^^^Tirso Pons^^^ and ^^^Wim Van den Ende^^^<br />
* [[Responsible Curator]]: ^^^Wim Van den Ende^^^<br />
----<br />
<br />
<!-- The data in the table below should be updated by the Author/Curator according to current information on the family --><br />
<div style="float:right"><br />
{| {{Prettytable}} <br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH68'''<br />
|-<br />
|'''Clan''' <br />
|GH-J<br />
|-<br />
|'''Mechanism'''<br />
|retaining<br />
|-<br />
|'''Active site residues'''<br />
|known<br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br />
|-<br />
| colspan="2" |http://www.cazy.org/fam/GH68.html<br />
|}<br />
</div><br />
<!-- This is the end of the table --><br />
<br />
<br />
== Substrate specificities ==<br />
Glycoside hydrolase family GH68 contains enzymes that hydrolyze fructose containing polysaccharides such as levansucrase (EC 2.4.1.10); β-fructofuranosidase (EC 3.2.1.26); and inulosucrase (EC 2.4.1.9)<br />
<br />
== Kinetics and Mechanism ==<br />
Content is to be added here.<br />
<br />
<br />
== Catalytic Residues ==<br />
Content is to be added here.<br />
<br />
<br />
== Three-dimensional structures ==<br />
Currently, only two different three dimensional structures of family GH68 enzymes have been solved so far. The first crystal structure was reported for the bacterial levansucrase (SacB) from Bacillus subtilis subsp. subtilis str. 168 <cite>X1</cite>. The second one corresponds to levansucrase (LdsA) from Gluconacetobacter diazotrophicus SRT4 <cite>X2</cite>.<br />
<br />
<br />
== Family Firsts ==<br />
;First stereochemistry determination: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite>Comfort2007</cite>.<br />
;First catalytic nucleophile identification: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite>MikesClassic</cite>.<br />
;First general acid/base residue identification: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite>He1999</cite>.<br />
;First 3-D structure: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite>3</cite>.<br />
<br />
== References ==<br />
You can even cite books using just the ISBN <cite>3</cite>. References that are not in PubMed can be typed in by hand <cite>MikesClassic</cite>. <br />
<br />
<biblio><br />
#X1 pmid=14517548<br />
#X2 pmid=15869470<br />
#3 isbn=978-0-240-52118-3<br />
#MikesClassic Sinnott, M.L. (1990) Catalytic mechanisms of enzymic glycosyl transfer. Chem. Rev. 90, 1171-1202. [http://dx.doi.org/10.1021/cr00105a006 DOI: 10.1021/cr00105a006]<br />
<br />
</biblio><br />
<br />
<br />
[[Category:Glycoside Hydrolase Families|GH068]]</div>Tirso Ponshttps://www.cazypedia.org/index.php?title=Glycoside_Hydrolase_Family_68&diff=3858Glycoside Hydrolase Family 682010-02-16T11:29:59Z<p>Tirso Pons: </p>
<hr />
<div><!-- CURATORS: Please replace the {{UnderConstruction}} tag below with {{CuratorApproved}} when the page is ready for wider public consumption --><br />
{{UnderConstruction}}<br />
* [[Author]]: ^^^Tirso Pons^^^ and ^^^Wim Van den Ende^^^<br />
* [[Responsible Curator]]: ^^^Wim Van den Ende^^^<br />
----<br />
<br />
<!-- The data in the table below should be updated by the Author/Curator according to current information on the family --><br />
<div style="float:right"><br />
{| {{Prettytable}} <br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH68'''<br />
|-<br />
|'''Clan''' <br />
|GH-J<br />
|-<br />
|'''Mechanism'''<br />
|retaining<br />
|-<br />
|'''Active site residues'''<br />
|known<br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br />
|-<br />
| colspan="2" |http://www.cazy.org/fam/GH68.html<br />
|}<br />
</div><br />
<!-- This is the end of the table --><br />
<br />
<br />
== Substrate specificities ==<br />
Glycoside hydrolase family GH68 contains enzymes that hydrolyze fructose containing polysaccharides such as levansucrase (EC 2.4.1.10); β-fructofuranosidase (EC 3.2.1.26); and inulosucrase (EC 2.4.1.9)<br />
<br />
This is an example of how to make references to a journal article <cite>Comfort2007</cite>. (See the References section below). Multiple references can go in the same place like this <cite>Comfort2007 He1999</cite>. You can even cite books using just the ISBN <cite>3</cite>. References that are not in PubMed can be typed in by hand <cite>MikesClassic</cite>. <br />
<br />
<br />
== Kinetics and Mechanism ==<br />
Content is to be added here.<br />
<br />
<br />
== Catalytic Residues ==<br />
Content is to be added here.<br />
<br />
<br />
== Three-dimensional structures ==<br />
Currently, only two different three dimensional structures of family GH68 enzymes have been solved so far. The first crystal structure was reported for the bacterial levansucrase (SacB) from Bacillus subtilis subsp. subtilis str. 168 <cite>X1</cite>. The second one corresponds to levansucrase (LdsA) from Gluconacetobacter diazotrophicus SRT4 <cite>X2</cite>.<br />
<br />
<br />
== Family Firsts ==<br />
;First stereochemistry determination: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite>Comfort2007</cite>.<br />
;First catalytic nucleophile identification: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite>MikesClassic</cite>.<br />
;First general acid/base residue identification: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite>He1999</cite>.<br />
;First 3-D structure: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite>3</cite>.<br />
<br />
== References ==<br />
<biblio><br />
#X1 pmid=14517548<br />
#X2 pmid=15869470<br />
#Comfort2007 pmid=17323919<br />
#He1999 pmid=9312086<br />
#3 isbn=978-0-240-52118-3<br />
#MikesClassic Sinnott, M.L. (1990) Catalytic mechanisms of enzymic glycosyl transfer. Chem. Rev. 90, 1171-1202. [http://dx.doi.org/10.1021/cr00105a006 DOI: 10.1021/cr00105a006]<br />
<br />
</biblio><br />
<br />
<br />
[[Category:Glycoside Hydrolase Families|GH068]]</div>Tirso Ponshttps://www.cazypedia.org/index.php?title=User:Tirso_Pons&diff=3857User:Tirso Pons2010-02-16T10:55:11Z<p>Tirso Pons: </p>
<hr />
<div>[[File:Tirso-02.jpg|200px|thumb|right|alt text]]<br />
'''Tirso Pons''' obtained his B.Sc. degree in Nuclear Physics from the Institute of Nuclear Sciences, Havana, then completed his Ph.D. in Biology at University of Havana with Joaquin Diaz and Alfonso Valencia in 2002, working on the sequence analysis, and structure and functional residues prediction for glycosyde hydrolase [[GH32]], [[GH49]] and [[GH68]] families. He and colleagues predicted for the first time a common beta-propeller fold for the catalytic domain in [[GH32]] and [[GH68]] families, and also proposed the aspartate residue in the conserved "Arg-Asp-Pro (RDP) motif" as a third residue important for catalysis. Through collaboration with Prof. ^^^Gideon Davies^^^ (York University, UK), he and colleagues determined the crystal structure of levansucrase from the gram-negative bacterium ''Gluconacetobacter diazotrophicus''. Tirso was a visiting scientist at Dr. Alfonso Valencia's Lab (CNB-CSIC) at the Autonomous University of Madrid, Spain, and at Dr. Gert Vriend's lab at the European Molecular Biology Laboratory (EMBL), Heidelberg, Germany.<br />
In 2007 and 2010 he obtained postdoctoral SEBiot and EMBO fellowships at the Structural Biology and Biocomputing Programme of the Spanish National Cancer Research Centre (CNIO), Madrid. He is currently an Associate Professor at Deparment of Biochemistry, and permanent researcher at the Center for Protein Research (CEP), Faculty of Biology, University of Havana.<br />
<br />
<br />
[[Category:Contributors|Pons,Tirso]]</div>Tirso Ponshttps://www.cazypedia.org/index.php?title=Glycoside_Hydrolase_Family_68&diff=3842Glycoside Hydrolase Family 682010-02-15T18:57:41Z<p>Tirso Pons: </p>
<hr />
<div><!-- CURATORS: Please replace the {{UnderConstruction}} tag below with {{CuratorApproved}} when the page is ready for wider public consumption --><br />
{{UnderConstruction}}<br />
* [[Author]]: ^^^Tirso Pons^^^ and ^^^Wim Van den Ende^^^<br />
* [[Responsible Curator]]: ^^^Wim Van den Ende^^^<br />
----<br />
<br />
<!-- The data in the table below should be updated by the Author/Curator according to current information on the family --><br />
<div style="float:right"><br />
{| {{Prettytable}} <br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH68'''<br />
|-<br />
|'''Clan''' <br />
|GH-J<br />
|-<br />
|'''Mechanism'''<br />
|retaining<br />
|-<br />
|'''Active site residues'''<br />
|known<br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br />
|-<br />
| colspan="2" |http://www.cazy.org/fam/GH68.html<br />
|}<br />
</div><br />
<!-- This is the end of the table --><br />
<br />
<br />
== Substrate specificities ==<br />
Glycoside hydrolase family GH68 contains enzymes that hydrolyze fructose containing polysaccharides such as levansucrase (EC 2.4.1.10); β-fructofuranosidase (EC 3.2.1.26); and inulosucrase (EC 2.4.1.9)<br />
<br />
This is an example of how to make references to a journal article <cite>Comfort2007</cite>. (See the References section below). Multiple references can go in the same place like this <cite>Comfort2007 He1999</cite>. You can even cite books using just the ISBN <cite>3</cite>. References that are not in PubMed can be typed in by hand <cite>MikesClassic</cite>. <br />
<br />
<br />
== Kinetics and Mechanism ==<br />
Content is to be added here.<br />
<br />
<br />
== Catalytic Residues ==<br />
Content is to be added here.<br />
<br />
<br />
== Three-dimensional structures ==<br />
Content is to be added here.<br />
<br />
<br />
== Family Firsts ==<br />
;First stereochemistry determination: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite>Comfort2007</cite>.<br />
;First catalytic nucleophile identification: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite>MikesClassic</cite>.<br />
;First general acid/base residue identification: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite>He1999</cite>.<br />
;First 3-D structure: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite>3</cite>.<br />
<br />
== References ==<br />
<biblio><br />
#Comfort2007 pmid=17323919<br />
#He1999 pmid=9312086<br />
#3 isbn=978-0-240-52118-3<br />
#MikesClassic Sinnott, M.L. (1990) Catalytic mechanisms of enzymic glycosyl transfer. Chem. Rev. 90, 1171-1202. [http://dx.doi.org/10.1021/cr00105a006 DOI: 10.1021/cr00105a006]<br />
<br />
</biblio><br />
<br />
<br />
[[Category:Glycoside Hydrolase Families|GH068]]</div>Tirso Ponshttps://www.cazypedia.org/index.php?title=Glycoside_Hydrolase_Family_68&diff=3841Glycoside Hydrolase Family 682010-02-15T18:55:35Z<p>Tirso Pons: </p>
<hr />
<div><!-- CURATORS: Please replace the {{UnderConstruction}} tag below with {{CuratorApproved}} when the page is ready for wider public consumption --><br />
{{UnderConstruction}}<br />
* [[Author]]: ^^^Tirso Pons^^^ and ^^^Wim Van den Ende^^^<br />
* [[Responsible Curator]]: ^^^Wim Van den Ende^^^<br />
----<br />
<br />
<!-- The data in the table below should be updated by the Author/Curator according to current information on the family --><br />
<div style="float:right"><br />
{| {{Prettytable}} <br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH68'''<br />
|-<br />
|'''Clan''' <br />
|GH-J<br />
|-<br />
|'''Mechanism'''<br />
|Retaining<br />
|-<br />
|'''Active site residues'''<br />
|known<br />
|-<br />
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br />
|-<br />
| colspan="2" |http://www.cazy.org/fam/GH68.html<br />
|}<br />
</div><br />
<!-- This is the end of the table --><br />
<br />
<br />
== Substrate specificities ==<br />
Glycoside hydrolase family GH68 contains enzymes that hydrolyze fructose containing polysaccharides such as levansucrase (EC 2.4.1.10); β-fructofuranosidase (EC 3.2.1.26); and inulosucrase (EC 2.4.1.9)<br />
<br />
This is an example of how to make references to a journal article <cite>Comfort2007</cite>. (See the References section below). Multiple references can go in the same place like this <cite>Comfort2007 He1999</cite>. You can even cite books using just the ISBN <cite>3</cite>. References that are not in PubMed can be typed in by hand <cite>MikesClassic</cite>. <br />
<br />
<br />
== Kinetics and Mechanism ==<br />
Content is to be added here.<br />
<br />
<br />
== Catalytic Residues ==<br />
Content is to be added here.<br />
<br />
<br />
== Three-dimensional structures ==<br />
Content is to be added here.<br />
<br />
<br />
== Family Firsts ==<br />
;First stereochemistry determination: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite>Comfort2007</cite>.<br />
;First catalytic nucleophile identification: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite>MikesClassic</cite>.<br />
;First general acid/base residue identification: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite>He1999</cite>.<br />
;First 3-D structure: Cite some reference here, with a ''short'' (1-2 sentence) explanation <cite>3</cite>.<br />
<br />
== References ==<br />
<biblio><br />
#Comfort2007 pmid=17323919<br />
#He1999 pmid=9312086<br />
#3 isbn=978-0-240-52118-3<br />
#MikesClassic Sinnott, M.L. (1990) Catalytic mechanisms of enzymic glycosyl transfer. Chem. Rev. 90, 1171-1202. [http://dx.doi.org/10.1021/cr00105a006 DOI: 10.1021/cr00105a006]<br />
<br />
</biblio><br />
<br />
<br />
[[Category:Glycoside Hydrolase Families|GH068]]</div>Tirso Pons