Glycoside Hydrolase Family 124 - Revision history

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

2021-12-18T21:18:57Z

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

Spencer Williams at 00:13, 17 November 2016

2016-11-17T00:13:29Z

Spencer Williams: /* Three-dimensional structures */

2016-11-17T00:12:18Z

Three-dimensional structures

Spencer Williams: /* Family Firsts */

2012-11-26T01:31:30Z

Family Firsts

Spencer Williams at 01:31, 26 November 2012

2012-11-26T01:31:06Z

Harry Brumer at 15:46, 30 April 2012

2012-04-30T15:46:16Z

Harry Brumer: /* Catalytic Residues */

2012-04-30T15:45:12Z

Catalytic Residues

Harry Brumer at 15:44, 30 April 2012

2012-04-30T15:44:37Z

Harry Brumer at 15:12, 30 April 2012

2012-04-30T15:12:04Z

Harry Gilbert at 09:44, 30 April 2012

2012-04-30T09:44:31Z

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 <!-- RESPONSIBLE CURATORS: Please replace the {{UnderConstruction}} tag below with {{CuratorApproved}} when the page is ready for wider public consumption -->
 {{CuratorApproved}}
-* [[Author]]: ^^^Harry Gilbert^^^
+* [[Author]]: [[User:Harry Gilbert|Harry Gilbert]]
-* [[Responsible Curator]]:  ^^^Harry Gilbert^^^
+* [[Responsible Curator]]:  [[User:Harry Gilbert|Harry Gilbert]]
 ----

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 == Substrate specificities ==
-Family GH124 consists of a small number of cellulosomal [[glycoside hydrolases]]. The ''Clostridium thermocellum'' enzyme ''Ct''Cel124A is the only member of this family that has been characterized. The enzyme is an ''[[endo]]''-&beta;1,4-glucanase with modest activity ''in vitro'', but acts in synergy with the major ''[[exo]]''-cellulase from ''C. thermocellum'' and, as a discrete entity, is able to deconstruct tobacco cell walls <cite>Bras2011</cite>.
+Family GH124 consists of a small number of celluloytic [[glycoside hydrolases]]. The ''Clostridium thermocellum'' enzyme ''Ct''Cel124A is the only member of this family that has been characterized. The enzyme is an ''[[endo]]''-&beta;1,4-glucanase with modest activity ''in vitro'', but acts in synergy with the major ''[[exo]]''-cellulase from ''C. thermocellum'' and, as a discrete entity, is able to deconstruct tobacco cell walls <cite>Bras2011</cite>.
 == Kinetics and Mechanism ==

@@ Line 38: / Line 38: @@
 == Three-dimensional structures ==
-The enzyme displays a superhelical fold in which a constellation of α-helices encircle a central helix that houses the catalytic apparatus. The catalytic acid, Glu96, is located at the C-terminus of the central helix. The substrate-binding cleft can be divided into two discrete topographical domains in which the bound cellotriose molecules display twisted and linear conformations, respectively, suggesting that the enzyme may target the interface between crystalline and disordered regions of cellulose. The active site of ''Ct''Cel124 displays remarkable structural conservation with a [[GH23]] lytic transglycosylase <cite>Bras2011</cite>.
+The enzyme displays a superhelical fold in which a constellation of α-helices encircling a central helix that houses the catalytic apparatus. This fold was described as having closest similarity to black swan lysozyme G (Lyz23) from family [[GH23]] <cite>Bras2011</cite>; similarities also exist to family [[GH19]] chitinases, family [[GH22]] lysozymes, and family [[GH134]] &beta;-mannanases. The catalytic acid, Glu96, is located at the C-terminus of the central helix. The substrate-binding cleft can be divided into two discrete topographical domains in which the bound cellotriose molecules display twisted and linear conformations, respectively, suggesting that the enzyme may target the interface between crystalline and disordered regions of cellulose. The active site of ''Ct''Cel124 displays remarkable structural conservation with a [[GH23]] lytic transglycosylase <cite>Bras2011</cite>.
 == Family Firsts ==

@@ Line 41: / Line 41: @@
 == Family Firsts ==
-;First stereochemistry determination: The sterochemical outcome of catalysis is [[inversion|inverting]] of the &beta; linkage into the &alpha; anomer <cite>Bras2011</cite>. The method used to detect the stereochemical outcome was the HPLC method of Braun et al. <cite>Braun1993</cite>. The reaction was too slow to detect through NMR as rapid mutarotation obscured the sterochemistry of glycosidic bond cleavage.
+;First stereochemistry determination: The sterochemical outcome of catalysis is [[inverting|inversion]] of the &beta; linkage into the &alpha; anomer <cite>Bras2011</cite>. The method used to detect the stereochemical outcome was the HPLC method of Braun et al. <cite>Braun1993</cite>. The reaction was too slow to detect through NMR as rapid mutarotation obscured the sterochemistry of glycosidic bond cleavage.
 ;First [[general base]] residue identification: The candidate catalytic base has not been identified.
 ;First [[general acid/base]] residue identification: The catalytic [[general acid]] was identified from analysis of structure in harness with mutagenesis data and sequence analysis <cite>Bras2011</cite>.

@@ Line 29: / Line 29: @@
 == Substrate specificities ==
-Family GH124 consists of a small number of cellulosomal proteins. The ''Clostridium thermocellum'' enzyme ''Ct''Cel124A is the only member of this family that has been characterized. The enzyme is an endo-&beta;1,4-glucanase with modest activity ''in vitro'', but acts in synergy with the major exo-cellulase from ''C. thermocellum'' and, as a discrete entity, is able to deconstruct tobacco cell walls <cite>Bras2011</cite>.
+Family GH124 consists of a small number of cellulosomal [[glycoside hydrolases]]. The ''Clostridium thermocellum'' enzyme ''Ct''Cel124A is the only member of this family that has been characterized. The enzyme is an ''[[endo]]''-&beta;1,4-glucanase with modest activity ''in vitro'', but acts in synergy with the major ''[[exo]]''-cellulase from ''C. thermocellum'' and, as a discrete entity, is able to deconstruct tobacco cell walls <cite>Bras2011</cite>.
 == Kinetics and Mechanism ==
-Using cellopentaose as the substrate and HPLC the enzyme was shown to display a single displacement (inverting) mechanism <cite>Bras2011</cite>.
+Using cellopentaose as the substrate and HPLC the enzyme was shown to utilize a single displacement, [[inverting]] mechanism <cite>Bras2011</cite>.
 == Catalytic Residues ==
-The catalytic acid in ''Ct''Cel124A was shown to be Glu96 based on the crystal structural of the enzyme and the observation that the E96A mutation completely inactivates the cellulase <cite>Bras2011</cite>. The enzyme contains no candidate catalytic base and it was suggested that the nucleophilic water was activated by a "Grotthus-like" mechanism, as previously proposed for some [[GH6]] cellulases <cite>Koivula2002</cite>.
+The catalytic [[general acid]] in ''Ct''Cel124A was shown to be Glu96 based on the crystal structural of the enzyme and the observation that the E96A mutation completely inactivates the cellulase <cite>Bras2011</cite>. The enzyme contains no candidate catalytic [[general base]] and it was suggested that the nucleophilic water was activated by a "Grotthus-like" mechanism, as previously proposed for some [[GH6]] cellulases <cite>Koivula2002</cite>.
 == Three-dimensional structures ==
-The enzyme displays a superhelical fold in which a constellation of α-helices encircle a central helix that houses the catalytic apparatus. The catalytic acid, Glu96, is located at the C-terminus of the central helix. The substrate-binding cleft can be divided into two discrete topographical domains in which the bound cellotriose molecules display twisted and linear conformations, respectively,
+The enzyme displays a superhelical fold in which a constellation of α-helices encircle a central helix that houses the catalytic apparatus. The catalytic acid, Glu96, is located at the C-terminus of the central helix. The substrate-binding cleft can be divided into two discrete topographical domains in which the bound cellotriose molecules display twisted and linear conformations, respectively, suggesting that the enzyme may target the interface between crystalline and disordered regions of cellulose. The active site of ''Ct''Cel124 displays remarkable structural conservation with a [[GH23]] lytic transglycosylase <cite>Bras2011</cite>.
 == Family Firsts ==
-;First stereochemistry determination: The sterochemical outcome of catalysis is inversion of the &beta; linkage into the &alpha; anomer <cite>Bras2011</cite>. The method used to detect the stereochemical outcome was the HPLC method of Braun et al. <cite>Braun1993</cite>. The reaction was too slow to detect through NMR as mutarotation obscured the sterochemistry of glycosidic bond cleavage.
+;First stereochemistry determination: The sterochemical outcome of catalysis is [[inversion|inverting]] of the &beta; linkage into the &alpha; anomer <cite>Bras2011</cite>. The method used to detect the stereochemical outcome was the HPLC method of Braun et al. <cite>Braun1993</cite>. The reaction was too slow to detect through NMR as rapid mutarotation obscured the sterochemistry of glycosidic bond cleavage.
-;First catalytic nucleophile identification: The candidate catalytic base has been identified.
+;First [[general base]] residue identification: The candidate catalytic base has not been identified.
-;First general acid/base residue identification: The catalytic acid was identified from structure in harness with mutagenesis and sequence conservation <cite>Bras2011</cite>.
+;First [[general acid/base]] residue identification: The catalytic [[general acid]] was identified from analysis of structure in harness with mutagenesis data and sequence analysis <cite>Bras2011</cite>.
-;First 3-D structure: The crystal structure of ''Ct''Cel124 was determined in complex with two cellotriose molecules. The structure revealed a novel cellulase fold and hinted that the enzyme attacks cellulose at the interface between two structural domains of the substrate <cite>Bras2011</cite>.
+;First 3-D structure: The X-ray crystal structure of ''Ct''Cel124 was determined in complex with two cellotriose molecules. The structure revealed a novel cellulase fold and hinted that the enzyme attacks cellulose at the interface between two structural domains of the substrate <cite>Bras2011</cite>.
 == References ==

@@ Line 35: / Line 35: @@
 == Catalytic Residues ==
-The catalytic acid in ''Ct''Cel124A was shown to be Glu96 based on the crystal structural of the enzyme and the observation that the E96A mutation completely inactivates the cellulase <cite>Bras2011</cite>. The enzyme contains no candidate catalytic base and it was suggested that the nucleophilic water was activated by a Grotthus”-like mechanism <cite>Koivula2002</cite>.
+The catalytic acid in ''Ct''Cel124A was shown to be Glu96 based on the crystal structural of the enzyme and the observation that the E96A mutation completely inactivates the cellulase <cite>Bras2011</cite>. The enzyme contains no candidate catalytic base and it was suggested that the nucleophilic water was activated by a "Grotthus-like" mechanism, similar to some [[GH6]] cellulases <cite>Koivula2002</cite>.
 == Three-dimensional structures ==
 The enzyme displays a superhelical fold in which a constellation of α-helices encircle a central helix that houses the catalytic apparatus. The catalytic acid, Glu96, is located at the C-terminus of the central helix. The substrate-binding cleft can be divided into two discrete topographical domains in which the bound cellotriose molecules display twisted and linear conformations, respectively,
-suggesting that the enzyme may target the interface between crystalline and disordered regions of cellulose. The active site of ''Ct''Cel124 displays remarkable structural conservation with a GH23 lytic transglycosylase.
+suggesting that the enzyme may target the interface between crystalline and disordered regions of cellulose. The active site of ''Ct''Cel124 displays remarkable structural conservation with a [[GH23]] lytic transglycosylase.
 == Family Firsts ==

@@ Line 12: / Line 12: @@
 |-
 |'''Clan'''
-|None|-
+|None
 |'''Mechanism'''
 |Inverting
@@ Line 29: / Line 30: @@
 == Substrate specificities ==
 Family GH124 consists of a small number of cellulosomal proteins. The ''Clostridium thermocellum'' enzyme ''Ct''Cel124A is the only member of this family that has been characterized. The enzyme is an endo-&beta;1,4-glucanase with modest activity ''in vitro'', but acts in synergy with the major exo-cellulase from ''C. thermocellum'' and, as a discrete entity, is able to deconstruct tobacco cell walls <cite>Bras2011</cite>.
 == Kinetics and Mechanism ==
 Using cellopentaose as the substrate and HPLC the enzyme was shown to display a single displacement (inverting) mechanism <cite>Bras2011</cite>.
 == Catalytic Residues ==
 The catalytic acid in ''Ct''Cel124A was shown to be Glu96 based on the crystal structural of the enzyme and the observation that the E96A mutation completely inactivates the cellulase <cite>Bras2011</cite>. The enzyme contains no candidate catalytic base and it was suggested that the nucleophilic water was activated by a Grotthus”-like mechanism <cite>Koivula2002</cite>.
 == Three-dimensional structures ==
@@ Line 45: / Line 42: @@
 == Family Firsts ==
-;First stereochemistry determination: The sterochemical outcome of catalysis is inversion of the &beta; linkage into the &alpha; anomer <cite>Bras2011</cite>. The method used to detect the stereochemical outcome was the HPLC method of Braun et al. <cite>3</cite>. The reaction was too slow to detect through NMR as mutarotation obscured the sterochemistry of glycosidic bond cleavage.
+;First stereochemistry determination: The sterochemical outcome of catalysis is inversion of the &beta; linkage into the &alpha; anomer <cite>Bras2011</cite>. The method used to detect the stereochemical outcome was the HPLC method of Braun et al. <cite>Braun1993</cite>. The reaction was too slow to detect through NMR as mutarotation obscured the sterochemistry of glycosidic bond cleavage.
 ;First catalytic nucleophile identification: The candidate catalytic base has been identified.
 ;First general acid/base residue identification: The catalytic acid was identified from structure in harness with mutagenesis and sequence conservation <cite>Bras2011</cite>.
@@ Line 54: / Line 51: @@
 #Bras2011 pmid=21393568
 #Koivula2002 pmid=12188666
-#3 pmid=8368500
+#Braun1993 pmid=8368500
 </biblio>
 [[Category:Glycoside Hydrolase Families|GH124]]