Glycoside Hydrolase Family 31 - Revision history

Spencer Williams: /* References */

2025-08-27T00:50:17Z

References

Spencer Williams: /* Substrate specificities */ added sentence and link to subfamily classification

2025-08-27T00:49:49Z

Substrate specificities: added sentence and link to subfamily classification

Spencer Williams at 05:18, 17 December 2023

2023-12-17T05:18:42Z

Spencer Williams at 06:13, 16 December 2023

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Spencer Williams at 05:50, 16 December 2023

2023-12-16T05:50:15Z

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

2021-12-18T21:17:49Z

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

Spencer Williams at 12:54, 18 September 2019

2019-09-18T12:54:23Z

Spencer Williams at 08:24, 21 March 2016

2016-03-21T08:24:00Z

Spencer Williams at 08:23, 21 March 2016

2016-03-21T08:23:41Z

Spencer Williams at 07:36, 27 February 2016

2016-02-27T07:36:24Z

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 #Larsbrink2012 pmid=22961810
 #Speciale2016 pmid=26878550
 </biblio>
 <!-- DO NOT REMOVE THIS CATEGORY TAG! -->
 [[Category:Glycoside Hydrolase Families|GH031]]

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 == Substrate specificities ==
-CAZy Family GH31 has been reviewed and classified on the basis of sequence and structures into subfamilies <cite>#Arumapperuma2023</cite>. Family GH13 is one of the two major families of [[glycoside hydrolases]], along with GH13, that contain &alpha;-glucosidases. These enzymes play important roles in primary metabolism (e.g. human sucrase/isomaltase, a target for diabetic drugs such as miglitol), in catabolism (e.g. human lysosomal &alpha;-glucosidase) and in glycoprotein processing (e.g. ER glucosidase II). In addition to &alpha;-glucosidases, GH31 also contains &alpha;-xylosidases, isomaltosyltransferases, maltase/glucoamylases and sulfoquinovosidases. Sulfoquinovosidases (SQases) cleave the &alpha;-glycosidic linkage of &alpha;-sulfoquinovosides (glycosides of 6-sulfoglucose), present within sulfoquinovosyl diacylglyceride, a sulfolipid produced by photosynthetic organisms including plants <cite>Speciale2016</cite>. SQases are also present in family [[GH188]]. Another mechanistically interesting activity is the non-hydrolytic [[Alpha-glucan lyases|&alpha;-glucan lyases]], which cleave &alpha;-glucans to give 1,5-anhydro-fructose. GH31 enzymes can be found in a wide range of organisms including archaea, bacteria, plants and animals. Interestingly the two mammalian digestive enzymes are both duplicated genes, each with dual specificities.
+CAZy Family GH31 has been reviewed and classified on the basis of sequence and structures into subfamilies <cite>#Arumapperuma2023</cite>. Family GH31 is one of the two major families of [[glycoside hydrolases]], along with GH13, that contain &alpha;-glucosidases. These enzymes play important roles in primary metabolism (e.g. human sucrase/isomaltase, a target for diabetic drugs such as miglitol), in catabolism (e.g. human lysosomal &alpha;-glucosidase) and in glycoprotein processing (e.g. ER glucosidase II). In addition to &alpha;-glucosidases, GH31 also contains &alpha;-xylosidases, isomaltosyltransferases, maltase/glucoamylases and sulfoquinovosidases. Sulfoquinovosidases (SQases) cleave the &alpha;-glycosidic linkage of &alpha;-sulfoquinovosides (glycosides of 6-sulfoglucose), present within sulfoquinovosyl diacylglyceride, a sulfolipid produced by photosynthetic organisms including plants <cite>Speciale2016</cite>. SQases are also present in family [[GH188]]. Another mechanistically interesting activity is the non-hydrolytic [[Alpha-glucan lyases|&alpha;-glucan lyases]], which cleave &alpha;-glucans to give 1,5-anhydro-fructose. GH31 enzymes are found in a wide range of organisms including archaea, bacteria, plants and animals. Interestingly the two human digestive GH31 enzymes are both duplicated genes, each with dual specificities. In light of the sequence and functional diversity of GH31 members, this family has been divided into subfamilies <cite>Arumapperuma2023</cite>.
 == Kinetics and Mechanism ==

@@ Line 26: / Line 26: @@
 == Substrate specificities ==
-CAZy Family GH31 has been reviewed and classified on the basis of sequence and structures into subfamilies <cite>#Arumapperuma2023</cite>. Family GH13 is one of the two major families of [[glycoside hydrolases]], along with GH13, that contain &alpha;-glucosidases. These enzymes play important roles in primary metabolism (e.g. human sucrase/isomaltase, a target for diabetic drugs such as miglitol), in catabolism (e.g. human lysosomal &alpha;-glucosidase) and in glycoprotein processing (e.g. ER glucosidase II). In addition to &alpha;-glucosidases, GH31 also contains &alpha;-xylosidases, isomaltosyltransferases, maltase/glucoamylases and sulfoquinovosidases. Sulfoquinovosidases (SQases) cleave the &alpha;-glycosidic linkage of &alpha;-sulfoquinovosides (glycosides of 6-sulfoglucose), present within sulfoquinovosyl diacylglyceride, a sulfolipid produced by photosynthetic organisms including plants <cite>Speciale2016</cite>. SQases are also present in family [[GH188]]. Another mechanistically interesting activity is the non-hydrolytic [[Alpha-glucan lyases|&alpha;-glucan lyases]]. GH31 enzymes can be found in a wide range of organisms including archaea, bacteria, plants and animals. Interestingly the two mammalian digestive enzymes are both duplicated genes, each with dual specificities.
+CAZy Family GH31 has been reviewed and classified on the basis of sequence and structures into subfamilies <cite>#Arumapperuma2023</cite>. Family GH13 is one of the two major families of [[glycoside hydrolases]], along with GH13, that contain &alpha;-glucosidases. These enzymes play important roles in primary metabolism (e.g. human sucrase/isomaltase, a target for diabetic drugs such as miglitol), in catabolism (e.g. human lysosomal &alpha;-glucosidase) and in glycoprotein processing (e.g. ER glucosidase II). In addition to &alpha;-glucosidases, GH31 also contains &alpha;-xylosidases, isomaltosyltransferases, maltase/glucoamylases and sulfoquinovosidases. Sulfoquinovosidases (SQases) cleave the &alpha;-glycosidic linkage of &alpha;-sulfoquinovosides (glycosides of 6-sulfoglucose), present within sulfoquinovosyl diacylglyceride, a sulfolipid produced by photosynthetic organisms including plants <cite>Speciale2016</cite>. SQases are also present in family [[GH188]]. Another mechanistically interesting activity is the non-hydrolytic [[Alpha-glucan lyases|&alpha;-glucan lyases]], which cleave &alpha;-glucans to give 1,5-anhydro-fructose. GH31 enzymes can be found in a wide range of organisms including archaea, bacteria, plants and animals. Interestingly the two mammalian digestive enzymes are both duplicated genes, each with dual specificities.
 == Kinetics and Mechanism ==

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 == Substrate specificities ==
-CAZy Family GH31 is one of the two major families of [[glycoside hydrolases]], along with GH13, that contain &alpha;-glucosidases. These enzymes play important roles in primary metabolism (e.g. human sucrase/isomaltase, a target for diabetic drugs such as miglitol), in catabolism (e.g. human lysosomal &alpha;-glucosidase) and in glycoprotein processing (e.g. ER glucosidase II). In addition to &alpha;-glucosidases, GH31 also contains &alpha;-xylosidases, isomaltosyltransferases, maltase/glucoamylases and sulfoquinovosidases [{{EClink}}3.2.1.199 3.2.1.199]. Sulfoquinovosidases (SQases) cleave the &alpha;-glycosidic linkage of &alpha;-sulfoquinovosides (glycosides of 6-sulfoglucose), present within sulfoquinovosyl diacylglyceride, a sulfolipid produced by photosynthetic organisms including plants <cite>Speciale2016</cite>. SQases are also present in family [[GH188]]. Another mechanistically interesting activity is the non-hydrolytic [[Alpha-glucan lyases|&alpha;-glucan lyases]]. GH31 enzymes can be found in a wide range of organisms including archaea, bacteria, plants and animals. Interestingly the two mammalian digestive enzymes are both duplicated genes, each with dual specificities.
+CAZy Family GH31 has been reviewed and classified on the basis of sequence and structures into subfamilies <cite>#Arumapperuma2023</cite>. Family GH13 is one of the two major families of [[glycoside hydrolases]], along with GH13, that contain &alpha;-glucosidases. These enzymes play important roles in primary metabolism (e.g. human sucrase/isomaltase, a target for diabetic drugs such as miglitol), in catabolism (e.g. human lysosomal &alpha;-glucosidase) and in glycoprotein processing (e.g. ER glucosidase II). In addition to &alpha;-glucosidases, GH31 also contains &alpha;-xylosidases, isomaltosyltransferases, maltase/glucoamylases and sulfoquinovosidases. Sulfoquinovosidases (SQases) cleave the &alpha;-glycosidic linkage of &alpha;-sulfoquinovosides (glycosides of 6-sulfoglucose), present within sulfoquinovosyl diacylglyceride, a sulfolipid produced by photosynthetic organisms including plants <cite>Speciale2016</cite>. SQases are also present in family [[GH188]]. Another mechanistically interesting activity is the non-hydrolytic [[Alpha-glucan lyases|&alpha;-glucan lyases]]. GH31 enzymes can be found in a wide range of organisms including archaea, bacteria, plants and animals. Interestingly the two mammalian digestive enzymes are both duplicated genes, each with dual specificities.
 == Kinetics and Mechanism ==
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 == References ==
 <biblio>
 #Chiba1979 pmid=376499
 #Frandsen1998 pmid=9620260

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 == Substrate specificities ==
-CAZy Family GH31 is one of the two major families of [[glycoside hydrolases]], along with GH13, that contain &alpha;-glucosidases. These enzymes play important roles in primary metabolism (e.g. human sucrase/isomaltase, a target for diabetic drugs such as miglitol), in catabolism (e.g. human lysosomal &alpha;-glucosidase) and in glycoprotein processing (e.g. ER glucosidase II). In addition to &alpha;-glucosidases, GH31 also contains &alpha;-xylosidases, isomaltosyltransferases, maltase/glucoamylases and sulfoquinovosidases [{{EClink}}3.2.1.199 3.2.1.199]. Sulfoquinovosidases cleave the &alpha;-glycosidic linkage of &alpha;-sulfoquinovosides (glycosides of 6-sulfoglucose), present within sulfoquinovosyl diacylglyceride, a sulfolipid produced by photosynthetic organisms including plants <cite>Speciale2016</cite>. Another mechanistically interesting activity is the non-hydrolytic [[Alpha-glucan lyases|&alpha;-glucan lyases]]. GH31 enzymes can be found in a wide range of organisms including archaea, bacteria, plants and animals. Interestingly the two mammalian digestive enzymes are both duplicated genes, each with dual specificities.
+CAZy Family GH31 is one of the two major families of [[glycoside hydrolases]], along with GH13, that contain &alpha;-glucosidases. These enzymes play important roles in primary metabolism (e.g. human sucrase/isomaltase, a target for diabetic drugs such as miglitol), in catabolism (e.g. human lysosomal &alpha;-glucosidase) and in glycoprotein processing (e.g. ER glucosidase II). In addition to &alpha;-glucosidases, GH31 also contains &alpha;-xylosidases, isomaltosyltransferases, maltase/glucoamylases and sulfoquinovosidases [{{EClink}}3.2.1.199 3.2.1.199]. Sulfoquinovosidases (SQases) cleave the &alpha;-glycosidic linkage of &alpha;-sulfoquinovosides (glycosides of 6-sulfoglucose), present within sulfoquinovosyl diacylglyceride, a sulfolipid produced by photosynthetic organisms including plants <cite>Speciale2016</cite>. SQases are also present in family [[GH188]]. Another mechanistically interesting activity is the non-hydrolytic [[Alpha-glucan lyases|&alpha;-glucan lyases]]. GH31 enzymes can be found in a wide range of organisms including archaea, bacteria, plants and animals. Interestingly the two mammalian digestive enzymes are both duplicated genes, each with dual specificities.
 == Kinetics and Mechanism ==

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 {{CuratorApproved}}
-* [[Author]]: ^^^Ran Zhang^^^, ^^^Spencer Williams^^^
+* [[Author]]: [[User:Ran Zhang|Ran Zhang]], [[User:Spencer Williams|Spencer Williams]]
 * [[Responsible Curator]]:  [[User:Steve Withers|Steve Withers]]
 ----

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 == Catalytic Residues ==
-Measurements of pH profiles suggested that two essential residues were involved in catalysis <cite>Frandsen1998 Lovering2005 Lee2003</cite>. Earlier active site-labeling studies employing conduritol B epoxide identified an invariant Asp residue as the [[catalytic nucleophile]], corresponding to Asp224 of ''Aspergillus niger'' &alpha;-glucosidase within the sequence IDM <cite>Iwanami1995 Hermans1991</cite>. This was confirmed by using the more reliable 5-fluoro-&alpha;-D-glucopyransyl fluoride reagent followed by subsequent peptide mapping by LC/MS-MS <cite>Lee2001</cite>.
+Measurements of pH profiles suggested that two essential residues were involved in catalysis <cite>Frandsen1998 Lovering2005 Lee2003</cite>. Earlier active site-labeling studies employing conduritol B epoxide identified an invariant Asp residue as the [[catalytic nucleophile]], corresponding to Asp224 of ''Aspergillus niger'' &alpha;-glucosidase within the sequence IDM <cite>Iwanami1995 Hermans1991</cite>. This was confirmed by using the more reliable 5-fluoro-&alpha;-D-glucopyranosyl fluoride reagent followed by subsequent peptide mapping by LC/MS-MS <cite>Lee2001</cite>.
 The [[general acid/base]] residue was first tentatively assigned as Asp647 in the ''Schizosaccharomyces pombe'' &alpha;-glucosidase based on sequence comparison and kinetic analysis of the mutants <cite>Okuyama2001</cite>. This was subsequently confirmed by the crystallographic studies on &alpha;-xylosidase (YicI) from ''Escherichia coli'' <cite>Lovering2005</cite> and successfully engineering YicI into the first &alpha;-thioglycoligase by mutating the corresponding general acid/base residue D482 <cite>Kim2006</cite>.

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 == Kinetics and Mechanism ==
-Enzymes of family GH31 are [[retaining]] &alpha;-glycosidases, as was first demonstrated by a combination of polarimetric and reducing sugar measurement <cite>Chiba1979</cite>. GH31 enzymes (except for the [[&alpha;-glucan lyases]]) are believed to follow the classical [[Koshland double-displacement mechanism]]. <cite>Frandsen1998</cite> This has been strongly supported by labeling of the [[catalytic nucleophile]] of several GH31 enzymes using conduritol B epoxide <cite>Iwanami1995</cite>, with early examples including rabbit intestinal sucrase/isomaltase <cite>Quaroni1976</cite> and human lysosomal &alpha;-glucosidase <cite>Hermans1991</cite>. Later studies on an &alpha;-glucosidase from ''Aspergillus niger'' <cite>Lee2001</cite>, an &alpha;-xylosidase from ''Escherichia coli'' <cite>Lovering2005</cite>, YihQ sulfoquinovosidase from ''Escherichia coli'' <cite>Speciale2016</cite>, and an &alpha;-xylosidase from ''Cellvibrio japonicus'' <cite>Larsbrink2011</cite> used the more reliable 5-fluoroglycosyl fluoride trapping reagents, which form catalytically competent [[intermediate]]s.  Subsequently, retention of the anomeric configuration was directly observed by H-1 NMR during the hydrolysis of a natural xylogluco-oligosaccharide substrate by ''C. japonicus'' Xyl31A <cite>Larsbrink2012</cite>, and of ''E. coli'' YihQ sulfoquinovosidase <cite>Speciale2016</cite>.
+Enzymes of family GH31 are [[retaining]] &alpha;-glycosidases, as was first demonstrated by a combination of polarimetric and reducing sugar measurement <cite>Chiba1979</cite>. GH31 enzymes (except for the [[&alpha;-glucan lyases]]) are believed to follow the classical [[Koshland double-displacement mechanism]]. <cite>Frandsen1998</cite> This has been strongly supported by labeling of the [[catalytic nucleophile]] of several GH31 enzymes using conduritol B epoxide <cite>Iwanami1995</cite>, with early examples including rabbit intestinal sucrase/isomaltase <cite>Quaroni1976</cite> and human lysosomal &alpha;-glucosidase <cite>Hermans1991</cite>. Later studies on an &alpha;-glucosidase from ''Aspergillus niger'' <cite>Lee2001</cite>, an &alpha;-xylosidase from ''Escherichia coli'' <cite>Lovering2005</cite>, YihQ sulfoquinovosidase from ''Escherichia coli'' <cite>Speciale2016</cite>, and an &alpha;-xylosidase from ''Cellvibrio japonicus'' <cite>Larsbrink2011</cite> used the more reliable 5-fluoroglycosyl fluoride trapping reagents, which form catalytically competent [[intermediate]]s.  Subsequently, retention of the anomeric configuration was directly observed by H-1 NMR during the hydrolysis of a natural xylogluco-oligosaccharide substrate by ''C. japonicus'' Xyl31A <cite>Larsbrink2012</cite>, and of a synthetic &alpha;-sulfoquinovoside by ''E. coli'' YihQ sulfoquinovosidase <cite>Speciale2016</cite>.
 The [[&alpha;-glucan lyases]] from GH31 cleave &alpha;-glucan polymers via an elimination mechanism to generate 1,5-anhydro-fructose (see [[Alpha-glucan lyases|Lexicon]]). Detailed mechanistic studies have been carried out on ''Gracilariopsis'' &alpha;-1,4-glucan lyase revealing a mechanism that involves a nucleophilic displacement as the first step, followed by syn-elimination as the second step <cite>Lee2002 Lee2003</cite>. Evidence for the first step includes trapping of the catalytically competent glycosyl-enzyme [[intermediate]] by 5-fluoro-&beta;-L-idopyranosyl fluoride and the observation of secondary kinetic isotope effects (KIEs) on both H-1 and H-2 of two &alpha;-glucoside substrates. Direct proof of the second elimination step was provided by the observation of a small primary KIE on C-2 by using a substrate for which the elimination step is rate-limiting, 5-fluoro-&alpha;-D-glucopyranosyl fluoride.