Glycoside Hydrolase Family 16 - Revision history

Harry Brumer: Text replacement - "\^\^\^(.*)\^\^\^" to "$1"

2021-12-18T21:18:57Z

Text replacement - "\^\^\^(.*)\^\^\^" to "$1"

Mirjam Czjzek at 15:43, 25 September 2019

2019-09-25T15:43:20Z

Harry Brumer at 18:42, 24 September 2019

2019-09-24T18:42:14Z

Harry Brumer at 18:40, 24 September 2019

2019-09-24T18:40:58Z

Harry Brumer at 02:53, 23 November 2016

2016-11-23T02:53:47Z

Harry Brumer at 02:51, 23 November 2016

2016-11-23T02:51:56Z

Harry Brumer at 16:57, 12 November 2015

2015-11-12T16:57:00Z

Harry Brumer: /* Substrate specificities */

2015-11-10T00:12:08Z

Substrate specificities

Harry Brumer at 19:30, 9 November 2015

2015-11-09T19:30:55Z

Harry Brumer at 19:29, 9 November 2015

2015-11-09T19:29:23Z

@@ Line 1: / Line 1: @@
 {{CuratorApproved}}
-* [[Author]]: [[User:JensEklof|Jens Ekl&ouml;f]] and ^^^Jan-Hendrik Hehemann^^^
+* [[Author]]: [[User:JensEklof|Jens Ekl&ouml;f]] and [[User:Jan-Hendrik Hehemann|Jan-Hendrik Hehemann]]
-* [[Responsible Curator]]:  ^^^Harry Brumer^^^
+* [[Responsible Curator]]:  [[User:Harry Brumer|Harry Brumer]]
 ----

@@ Line 38: / Line 38: @@
 Notably, some members of GH16 are predominant [[transglycosylases]].  These include the plant xyloglucan:xyloglucosyltransferases (EC [{{EClink}}2.4.1.207 2.4.1.207], a.k.a. xyloglucan endo-transglycosylases, XETs) <cite>Eklof2010</cite> and yeast chitin/beta-glucan crosslinking enzymes Crh1 and Crh2 <cite>Cabib2008 Mazan2013 Blanco2015</cite>. Some invertebrate GH16 proteins have lost their catalytic amino acids and are involved in immune response activation through the Toll pathway upon binding of &beta;-1,3 glucan. The role of the GH16 domain in this immune response has not been fully elucidated <cite>Lee2009</cite>.
-Several of the activities observed for GH16 members are delineated into individual sequence-based subfamiliies, while other polyspecific subfamilies capture a range of activities <cite>Viborg2019</cite>.
+Several of the activities observed for GH16 members are delineated into individual sequence-based subfamilies, while other polyspecific subfamilies capture a range of activities <cite>Viborg2019</cite>.
 <gallery widths=270px perrow=3 caption="Diverse polysaccharides cleaved by GH16 enzymes">

@@ Line 36: / Line 36: @@
 * endo-xyloglucanases (EC [{{EClink}}3.2.1.151 3.2.1.151], a.k.a. xyloglucan endo-hydrolases, XEHs, in plants <cite>Eklof2010</cite>).
-Notably, some members of GH16 are predominant [[transglycosylases]].  These include the plant xyloglucan:xyloglucosyltransferases (EC [{{EClink}}2.4.1.207 2.4.1.207], a.k.a. xyloglucan endo-transglycosylases, XETs) <cite>Eklof2010</cite> and yeast chitin/beta-glucan crosslinking enzymes Crh1 and Crh2 <cite>Cabib2008 Mazan2013 Blanco2015</cite>.
+Notably, some members of GH16 are predominant [[transglycosylases]].  These include the plant xyloglucan:xyloglucosyltransferases (EC [{{EClink}}2.4.1.207 2.4.1.207], a.k.a. xyloglucan endo-transglycosylases, XETs) <cite>Eklof2010</cite> and yeast chitin/beta-glucan crosslinking enzymes Crh1 and Crh2 <cite>Cabib2008 Mazan2013 Blanco2015</cite>. Some invertebrate GH16 proteins have lost their catalytic amino acids and are involved in immune response activation through the Toll pathway upon binding of &beta;-1,3 glucan. The role of the GH16 domain in this immune response has not been fully elucidated <cite>Lee2009</cite>.
 Several of the activities observed for GH16 members are delineated into individual sequence-based subfamiliies, while other polyspecific subfamilies capture a range of activities <cite>Viborg2019</cite>.

@@ Line 39: / Line 39: @@
 Some invertebrate GH16 proteins have lost their catalytic amino acids and are involved in immune response activation through the Toll pathway upon binding of &beta;-1,3 glucan. The role of the GH16 domain in this immune response has not been fully elucidated <cite>Lee2009</cite>.
 <gallery widths=270px perrow=3 caption="Diverse polysaccharides cleaved by GH16 enzymes">
@@ Line 74: / Line 76: @@
 Proteins in GH16 share a β-jelly-roll fold in which two β-sheets align in a curved, sandwich-like manner and present a cleft-shaped active-site bounded by loops extending from the β-strands. The first solved 3D structure was a hybrid protein of licheninase M from ''Paenibacillus macerans'' and BglA from ''Bacillus amyloliquefaciens'' ([{{PDBlink}}1byh PDB 1byh]) in 1992 <cite>Keitel1993</cite>. Many three-dimensional structures have been solved of family 16 members of archeal, bacterial, and eukaryotic origin (see http://www.cazy.org/GH16_structure.html for an updated list).  Of these, the first eukaryotic 3D structure was the xyloglucan ''endo''-transglycosylase ''Ptt''XET16-34 from ''Populus tremula&times;tremuloides'' ([{{PDBlink}}1umz PDB 1umz]) <cite>Johansson2004</cite> and the first archeal 3D structure was a ''[[endo]]''-1,3-&beta;-glucanase Lam16 from ''Pyrococcus furiosus'' ([{{PDBlink}}2vy0 PDB 2vy0]) <cite>Ilari2009</cite>.
 == Evolution of GH16 ==
 [[Image:TreeGH16new.png|thumb|right|450px|'''Figure 1. Proposed evolution of GH16 (''click to enlarge'').''']]
-GH16 is a member of [[clans|clan]] GH-B together with  [[GH7]]; both families share the &beta;-jellyroll fold. The different specificities of GH16 are proposed to have evolved from an ancestral &beta;-1,3-glucanase <cite>Barbeyron1998</cite>. This proposal was elaborated using a structure-based phylogeny approach, which suggested that a first branching event lead to the evolution of the bacterial &kappa;-carrageenases and the &beta;-agarases, while a later branching event lead to the bacterial licheninases and the plant XETs <cite>Michel2001</cite> (Figure 1). In particular, the GH16 active-site residues are located in-train on one beta-strand at the center of the substrate binding cleft. Depending upon the phylogenetic clade, this beta-strand features one of two topologies.  The beta-bulge motif, which has the consensus sequence EXDXXE, is more frequent in GH16 compared to the regular beta-strand with the consensus sequence EXDXE (the [[catalytic nucleophile]] is the first glutamate and the [[catalytic acid/base]] is the second, with a proposed "helper" asparate in-between <cite>Planas2000</cite>). Due to the predominance of the beta-bulge motif and its presence as the only motif in [[GH7]], Michel et al. proposed that the beta-bulge is the ancestral motif, which subsequently gave rise to the regular beta-strand of extant XETs and licheninases <cite>Michel2001</cite>.  More recently, similar structure-based phylogenetic approaches have suggested that XEHs evolved subsequently to XEHs within the ''xyloglucan endo-transglycosylase/hydrolase (XTH)'' gene family in plant lineages <cite>Baumann2007 Eklof2010</cite>, while the more recent identification of a group of bifunctional GH16 [[glycoside hydrolases]], which is active on both mixed-linkage beta-glucan and xyloglucan, provides additional support for the close evolutionary relationship of XETs and licheninases <cite>Eklof2013 McGregor2016</cite>.
+GH16 is a member of [[clans|clan]] GH-B together with  [[GH7]]; both families share the &beta;-jellyroll fold. The different specificities of GH16 are proposed to have evolved from an ancestral &beta;-1,3-glucanase <cite>Barbeyron1998</cite>. This proposal was first elaborated using a structure-based phylogeny approach, which suggested that an early branching event lead to the evolution of the bacterial &kappa;-carrageenases and the &beta;-agarases, while a later branching event lead to the bacterial licheninases and the plant XETs <cite>Michel2001</cite> (Figure 1). GH16 has more recently been divided into subfamilies within CAZy, the corresponding phylogenetic analysis of which supports this overall evolutionary trajectory <cite>Viborg2019</cite>.
 == Family firsts ==
@@ Line 110: / Line 117: @@
 #Bissaro2015 pmid=25793417
 #McGregor2016 pmid=27859885
 </biblio>
 <!-- DO NOT REMOVE THIS CATEGORY TAG! -->
 [[Category:Glycoside Hydrolase Families|GH016]]

@@ Line 76: / Line 76: @@
 == Evolution of GH16 ==
 [[Image:TreeGH16new.png|thumb|right|450px|'''Figure 1. Proposed evolution of GH16 (''click to enlarge'').''']]
-GH16 is a member of [[clans|clan]] GH-B together with  [[GH7]]; both families share the &beta;-jellyroll fold. The different specificities of GH16 are proposed to have evolved from an ancestral &beta;-1,3-glucanase <cite>Barbeyron1998</cite>. This proposal was elaborated using a structure-based phylogeny approach, which suggested that a first branching event lead to the evolution of the bacterial &kappa;-carrageenases and the &beta;-agarases, while a later branching event lead to the bacterial licheninases and the plant XETs <cite>Michel2001</cite> (Figure 1). In particular, the GH16 active-site residues are located in-train on one beta-strand at the center of the substrate binding cleft. Depending upon the phylogenetic clade, this beta-strand features one of two topologies.  The beta-bulge motif, which has the consensus sequence EXDXXE, is more frequent in GH16 compared to the regular beta-strand with the consensus sequence EXDXE (the [[catalytic nucleophile]] is the first glutamate and the [[catalytic acid/base]] is the second, with a proposed "helper" asparate in-between <cite>Planas2000</cite>). Due to the predominance of the beta-bulge motif and its presence as the only motif in [[GH7]], Michel et al. proposed that the beta-bulge is the ancestral motif, which subsequently gave rise to the regular beta-strand of extant XETs and licheninases <cite>Michel2001</cite>.  More recently, similar structure-based phylogenetic approaches have suggested that XEHs evolved subsequently to XEHs within the ''xyloglucan endo-transglycosylase/hydrolase (XTH)'' gene family in plant lineages <cite>Baumann2007 Eklof2010</cite>, while the recent identification of a group of bifunctional GH16 [[glycoside hydrolases]], which is active on both mixed-linkage beta-glucan and xyloglucan, provides additional support for the close evolutionary relationship of XETs and licheninases <cite>Eklof2013 McGregor2016</cite>.
+GH16 is a member of [[clans|clan]] GH-B together with  [[GH7]]; both families share the &beta;-jellyroll fold. The different specificities of GH16 are proposed to have evolved from an ancestral &beta;-1,3-glucanase <cite>Barbeyron1998</cite>. This proposal was elaborated using a structure-based phylogeny approach, which suggested that a first branching event lead to the evolution of the bacterial &kappa;-carrageenases and the &beta;-agarases, while a later branching event lead to the bacterial licheninases and the plant XETs <cite>Michel2001</cite> (Figure 1). In particular, the GH16 active-site residues are located in-train on one beta-strand at the center of the substrate binding cleft. Depending upon the phylogenetic clade, this beta-strand features one of two topologies.  The beta-bulge motif, which has the consensus sequence EXDXXE, is more frequent in GH16 compared to the regular beta-strand with the consensus sequence EXDXE (the [[catalytic nucleophile]] is the first glutamate and the [[catalytic acid/base]] is the second, with a proposed "helper" asparate in-between <cite>Planas2000</cite>). Due to the predominance of the beta-bulge motif and its presence as the only motif in [[GH7]], Michel et al. proposed that the beta-bulge is the ancestral motif, which subsequently gave rise to the regular beta-strand of extant XETs and licheninases <cite>Michel2001</cite>.  More recently, similar structure-based phylogenetic approaches have suggested that XEHs evolved subsequently to XEHs within the ''xyloglucan endo-transglycosylase/hydrolase (XTH)'' gene family in plant lineages <cite>Baumann2007 Eklof2010</cite>, while the more recent identification of a group of bifunctional GH16 [[glycoside hydrolases]], which is active on both mixed-linkage beta-glucan and xyloglucan, provides additional support for the close evolutionary relationship of XETs and licheninases <cite>Eklof2013 McGregor2016</cite>.
 == Family firsts ==

@@ Line 64: / Line 64: @@
 == Kinetics and Mechanism ==
-Members of GH16 enzymes are [[retaining]] enzymes, as first shown by NMR <cite>Malet1993</cite> on an ''[[endo]]''-1,3-1,4-&beta;-D-glucan 4-glucanohydrolase from ''Bacillus licheniformis''. As such, they utilize a covalent glycosyl-enzyme intermediate, which is broken-down by glycosyl transfer <cite>Sinnott1990</cite> to water or a carbohydrate acceptor substrate in [[glycoside hydrolases]] or [[transglycosylases]], respectively.
+Members of GH16 enzymes are [[retaining]] enzymes, as first shown by NMR <cite>Malet1993</cite> on an ''[[endo]]''-1,3-1,4-&beta;-D-glucan 4-glucanohydrolase from ''Bacillus licheniformis''. As such, they utilize a covalent glycosyl-enzyme intermediate, which is broken-down by glycosyl transfer <cite>Sinnott1990 Bissaro2015</cite> to water or a carbohydrate acceptor substrate in [[glycoside hydrolases]] or [[transglycosylases]], respectively.
 == Catalytic Residues ==
@@ Line 108: / Line 108: @@
 #Piens2007 pmid=18043802
 #Eklof2013 pmid=23572521
 </biblio>
 <!-- DO NOT REMOVE THIS CATEGORY TAG! -->
 [[Category:Glycoside Hydrolase Families|GH016]]

@@ Line 25: / Line 25: @@
 == Substrate specificities ==
-The members of family 16 are active on &beta;-1,4 or &beta;-1,3 glycosidic bonds in various glucans and galactans. A wide diversity of [[glycoside hydrolases]] active on plant and marine polysaccharides are found in GH16, including: keratan-sulfate ''[[endo]]''-1,4-&beta;-galactosidases (EC [{{EClink}}3.2.1.103 3.2.1.103]), ''[[endo]]''-1,3-&beta;-galactanases (EC [{{EClink}}3.2.1.* 3.2.1.-]), ''[[endo]]''-1,3-&beta;-glucanases (EC [{{EClink}}3.2.1.39 3.2.1.39]), ''[[endo]]''-1,3(4)-&beta;-glucanases (EC [{{EClink}}3.2.1.6 3.2.1.6]), licheninases (EC [{{EClink}}3.2.1.73 3.2.1.73]), &beta;-agarases (EC [{{EClink}}3.2.1.81 3.2.1.81]), &beta;-porphyranases (EC [{{EClink}}3.2.1.178 3.2.1.178]) <cite>Hehemann2010</cite>, &kappa;-carrageenases (EC [{{EClink}}3.2.1.83 3.2.1.83]), and endo-xyloglucanases (EC [{{EClink}}3.2.1.151 3.2.1.151], a.k.a. xyloglucan endo-hydrolases, XEHs, in plants <cite>Eklof2010</cite>).
+The members of family 16 are active on &beta;-1,4 or &beta;-1,3 glycosidic bonds in various glucans and galactans. A wide diversity of [[glycoside hydrolases]] active on plant and marine polysaccharides are found in GH16, including:
 Notably, some members of GH16 are predominant [[transglycosylases]].  These include the plant xyloglucan:xyloglucosyltransferases (EC [{{EClink}}2.4.1.207 2.4.1.207], a.k.a. xyloglucan endo-transglycosylases, XETs) <cite>Eklof2010</cite> and yeast chitin/beta-glucan crosslinking enzymes Crh1 and Crh2 <cite>Cabib2008 Mazan2013 Blanco2015</cite>.

@@ Line 25: / Line 25: @@
 == Substrate specificities ==
-The members of family 16 are active on &beta;-1,4 or &beta;-1,3 glycosidic bonds in various glucans and galactans. A wide diversity of [[glycoside hydrolases]] active on plant and marine polysaccharides are found in GH16, including: keratan-sulfate ''[[endo]]''-1,4-&beta;-galactosidases (EC [{{EClink}}3.2.1.103 3.2.1.103]), ''[[endo]]''-1,3-&beta;-galactanases (EC [{{EClink}}3.2.1.* 3.2.1.-]), ''[[endo]]''-1,3-&beta;-glucanases (EC [{{EClink}}3.2.1.39 3.2.1.39]), ''[[endo]]''-1,3(4)-&beta;-glucanases (EC [{{EClink}}3.2.1.6 3.2.1.6]), lichenases (EC [{{EClink}}3.2.1.73 3.2.1.73]), &beta;-agarases (EC [{{EClink}}3.2.1.81 3.2.1.81]), &beta;-porphyranases (EC [{{EClink}}3.2.1.178 3.2.1.178]) <cite>Hehemann2010</cite>, &kappa;-carrageenases (EC [{{EClink}}3.2.1.83 3.2.1.83]), and endo-xyloglucanases (EC [{{EClink}}3.2.1.151 3.2.1.151], a.k.a. xyloglucan endo-hydrolases, XEHs)
+The members of family 16 are active on &beta;-1,4 or &beta;-1,3 glycosidic bonds in various glucans and galactans. A wide diversity of [[glycoside hydrolases]] active on plant and marine polysaccharides are found in GH16, including: keratan-sulfate ''[[endo]]''-1,4-&beta;-galactosidases (EC [{{EClink}}3.2.1.103 3.2.1.103]), ''[[endo]]''-1,3-&beta;-galactanases (EC [{{EClink}}3.2.1.* 3.2.1.-]), ''[[endo]]''-1,3-&beta;-glucanases (EC [{{EClink}}3.2.1.39 3.2.1.39]), ''[[endo]]''-1,3(4)-&beta;-glucanases (EC [{{EClink}}3.2.1.6 3.2.1.6]), licheninases (EC [{{EClink}}3.2.1.73 3.2.1.73]), &beta;-agarases (EC [{{EClink}}3.2.1.81 3.2.1.81]), &beta;-porphyranases (EC [{{EClink}}3.2.1.178 3.2.1.178]) <cite>Hehemann2010</cite>, &kappa;-carrageenases (EC [{{EClink}}3.2.1.83 3.2.1.83]), and endo-xyloglucanases (EC [{{EClink}}3.2.1.151 3.2.1.151], a.k.a. xyloglucan endo-hydrolases, XEHs)
 Notably, some members of GH16 are predominant [[transglycosylases]].  These include the plant xyloglucan:xyloglucosyltransferases (EC [{{EClink}}2.4.1.207 2.4.1.207], a.k.a. xyloglucan endo-transglycosylases, XETs) <cite>Eklof2010</cite> and yeast chitin/beta-glucan crosslinking enzymes Crh1 and Crh2 <cite>Cabib2008 Mazan2013 Blanco2015</cite>.
@@ Line 63: / Line 63: @@
 == Three-dimensional structures ==
-Proteins in GH16 share a β-jelly-roll fold in which two β-sheets align in a curved, sandwich-like manner and present a cleft-shaped active-site bounded by loops extending from the β-strands. The first solved 3D structure was a hybrid protein of lichenase M from ''Paenibacillus macerans'' and BglA from ''Bacillus amyloliquefaciens'' ([{{PDBlink}}1byh PDB 1byh]) in 1992 <cite>Keitel1993</cite>. Many three-dimensional structures have been solved of family 16 members of archeal, bacterial, and eukaryotic origin (see http://www.cazy.org/GH16_structure.html for an updated list).  Of these, the first eukaryotic 3D structure was the xyloglucan ''endo''-transglycosylase ''Ptt''XET16-34 from ''Populus tremula&times;tremuloides'' ([{{PDBlink}}1umz PDB 1umz]) <cite>Johansson2004</cite> and the first archeal 3D structure was a ''[[endo]]''-1,3-&beta;-glucanase Lam16 from ''Pyrococcus furiosus'' ([{{PDBlink}}2vy0 PDB 2vy0]) <cite>Ilari2009</cite>.
+Proteins in GH16 share a β-jelly-roll fold in which two β-sheets align in a curved, sandwich-like manner and present a cleft-shaped active-site bounded by loops extending from the β-strands. The first solved 3D structure was a hybrid protein of licheninase M from ''Paenibacillus macerans'' and BglA from ''Bacillus amyloliquefaciens'' ([{{PDBlink}}1byh PDB 1byh]) in 1992 <cite>Keitel1993</cite>. Many three-dimensional structures have been solved of family 16 members of archeal, bacterial, and eukaryotic origin (see http://www.cazy.org/GH16_structure.html for an updated list).  Of these, the first eukaryotic 3D structure was the xyloglucan ''endo''-transglycosylase ''Ptt''XET16-34 from ''Populus tremula&times;tremuloides'' ([{{PDBlink}}1umz PDB 1umz]) <cite>Johansson2004</cite> and the first archeal 3D structure was a ''[[endo]]''-1,3-&beta;-glucanase Lam16 from ''Pyrococcus furiosus'' ([{{PDBlink}}2vy0 PDB 2vy0]) <cite>Ilari2009</cite>.
 == Evolution of GH16 ==
-[[Image:TreeGH16new.png|thumb|right|450px|'''Figure 1. Proposed evolution of GH16 (''click to enlarge'')''']]
+[[Image:TreeGH16new.png|thumb|right|450px|'''Figure 1. Proposed evolution of GH16 (''click to enlarge'').''']]
-GH16 is a member of [[clans|clan]] GH-B together with  [[GH7]]; both families share the &beta;-jellyroll fold. The different specificities of GH16 are proposed to have evolved from an ancestral &beta;-1,3-glucanase <cite>Barbeyron1998</cite>. This proposal was elaborated using a structure-based phylogeny approach, which suggested that a first branching event lead to the evolution of the bacterial &kappa;-carrageenases and the &beta;-agarases, while a later branching event lead to the bacterial lichenases and the plant XETs <cite>Michel2001</cite> (Figure 1). In particular, the GH16 active-site residues are located in-train on one beta-strand at the center of the substrate binding cleft. Depending upon the phylogenetic clade, this beta-strand features one of two topologies.  The beta-bulge motif, which has the consensus sequence EXDXXE, is more frequent in GH16 compared to the regular beta-strand with the consensus sequence EXDXE (the [[catalytic nucleophile]] is the first glutamate and the [[catalytic acid/base]] is the second, with a proposed "helper" asparate in-between <cite>Planas2000</cite>). Due to the predominance of the beta-bulge motif and its presence as the only motif in [[GH7]], Michel et al. proposed that the beta-bulge is the ancestral motif, which subsequently gave rise to the regular beta-strand of extant XETs and lichenases <cite>Michel2001</cite>.  More recently, similar structure-based phylogenetic approaches have suggested that XEHs evolved subsequently to XEHs within the ''xyloglucan endo-transglycosylase/hydrolase (XTH)'' gene family in plant lineages <cite>Baumann2007 Eklof2010</cite>, while the recent identification of a group of bifunctional GH16 [[glycoside hydrolases]], which is active on both mixed-linkage beta-glucan and xyloglucan, provides additional support for the close evolutionary relationship of XETs and licheninases <cite>Eklof2013</cite>.
+GH16 is a member of [[clans|clan]] GH-B together with  [[GH7]]; both families share the &beta;-jellyroll fold. The different specificities of GH16 are proposed to have evolved from an ancestral &beta;-1,3-glucanase <cite>Barbeyron1998</cite>. This proposal was elaborated using a structure-based phylogeny approach, which suggested that a first branching event lead to the evolution of the bacterial &kappa;-carrageenases and the &beta;-agarases, while a later branching event lead to the bacterial licheninases and the plant XETs <cite>Michel2001</cite> (Figure 1). In particular, the GH16 active-site residues are located in-train on one beta-strand at the center of the substrate binding cleft. Depending upon the phylogenetic clade, this beta-strand features one of two topologies.  The beta-bulge motif, which has the consensus sequence EXDXXE, is more frequent in GH16 compared to the regular beta-strand with the consensus sequence EXDXE (the [[catalytic nucleophile]] is the first glutamate and the [[catalytic acid/base]] is the second, with a proposed "helper" asparate in-between <cite>Planas2000</cite>). Due to the predominance of the beta-bulge motif and its presence as the only motif in [[GH7]], Michel et al. proposed that the beta-bulge is the ancestral motif, which subsequently gave rise to the regular beta-strand of extant XETs and licheninases <cite>Michel2001</cite>.  More recently, similar structure-based phylogenetic approaches have suggested that XEHs evolved subsequently to XEHs within the ''xyloglucan endo-transglycosylase/hydrolase (XTH)'' gene family in plant lineages <cite>Baumann2007 Eklof2010</cite>, while the recent identification of a group of bifunctional GH16 [[glycoside hydrolases]], which is active on both mixed-linkage beta-glucan and xyloglucan, provides additional support for the close evolutionary relationship of XETs and licheninases <cite>Eklof2013</cite>.
 == Family firsts ==
@@ Line 73: / Line 73: @@
 ; First [[catalytic nucleophile]] identification : Suggested in  ''Bacillus amyloliquefaciens'' 1,3-1,4-&beta;-D-glucan 4-glucanohydrolase via non-specific epoxyalkyl β-glycoside labeling <cite>Hoj1992</cite>. Later verified by azide rescue of inactivated mutants <cite>Viladot1998</cite>.
 ; First [[general acid/base]] residue identification : ''Bacillus licheniformis'' 1,3-1,4-&beta;-D-glucan 4-glucanohydrolase, first suggested by sequence homology and mutational studies <cite>Juncosa1994</cite>. This was later verified by azide rescue of inactivated mutants <cite>Viladot1998</cite>.
-; First 3-D structure : A hybrid lichenase (''Bacillus amyloliquefaciens'' and ''Paenibacillus macerans'')  by X-ray crystallography ([{{PDBlink}}1byh PDB 1byh]) <cite>Keitel1993</cite>.
+; First 3-D structure : A hybrid licheninase (''Bacillus amyloliquefaciens'' and ''Paenibacillus macerans'')  by X-ray crystallography ([{{PDBlink}}1byh PDB 1byh]) <cite>Keitel1993</cite>.
 == Reference list ==