Home News About DMDM Database Statistics Research Publications Contact  

  Domain Name: GH31
The enzymes of glycosyl hydrolase family 31 (GH31) occur in prokaryotes, eukaryotes, and archaea with a wide range of hydrolytic activities, including alpha-glucosidase (glucoamylase and sucrase-isomaltase), alpha-xylosidase, 6-alpha-glucosyltransferase, 3-alpha-isomaltosyltransferase and alpha-1,4-glucan lyase. All GH31 enzymes cleave a terminal carbohydrate moiety from a substrate that varies considerably in size, depending on the enzyme, and may be either a starch or a glycoprotein. In most cases, the pyranose moiety recognized in subsite -1 of the substrate binding site is an alpha-D-glucose, though some GH31 family members show a preference for alpha-D-xylose. Several GH31 enzymes can accommodate both glucose and xylose and different levels of discrimination between the two have been observed. Most characterized GH31 enzymes are alpha-glucosidases. In mammals, GH31 members with alpha-glucosidase activity are implicated in at least three distinct biological processes. The lysosomal acid alpha-glucosidase (GAA) is essential for glycogen degradation and a deficiency or malfunction of this enzyme causes glycogen storage disease II, also known as pompe disease. In the endoplasmic reticulum, alpha-glucosidase II catalyzes the second step in the N-linked oligosaccharide processing pathway that constitutes part of the quality control system for glycoprotein folding and maturation. The intestinal enzymes sucrase-isomaltase (SI) and maltase-glucoamylase (MGAM) play key roles in the final stage of carbohydrate digestion, making alpha-glucosidase inhibitors useful in the treatment of type 2 diabetes. GH31 alpha-glycosidases are retaining enzymes that cleave their substrates via an acid/base-catalyzed, double-displacement mechanism involving a covalent glycosyl-enzyme intermediate. Two aspartic acid residues have been identified as the catalytic nucleophile and the acid/base, respectively.
No pairwise interactions are available for this conserved domain.

Total Mutations Found: 17
Total Disease Mutations Found: 9
This domain occurred 7 times on human genes (10 proteins).


 If you've navigated here from a protein, hovering over a position on the weblogo will display the corresponding protein position for that domain position.

 The histograms below the weblogo indicate mutations found on the domain. Red is for disease (OMIM) and blue is for SNPs.

 Functional Features are displayed as orange boxes under the histograms. You can choose which features are displayed in the box below.

Range on the Protein:  

   Protein ID            Protein Position

Domain Position:  

Feature Name:Total Found:
active site
catalytic site

Weblogos are Copyright (c) 2002 Regents of the University of California

Please Cite: Peterson, T.A., Adadey, A., Santana-Cruz ,I., Sun, Y., Winder A, Kann, M.G., (2010) DMDM: Domain Mapping of Disease Mutations. Bioinformatics 26 (19), 2458-2459.

   |   1000 Hilltop Circle, Baltimore, MD 21250   |   Department of Biological Sciences   |   Phone: 410-455-2258