glycosyl hydrolase family 31 (GH31); uncharacterized subgroup. This family represents an uncharacterized GH31 enzyme subgroup found in bacteria and eukaryotes. Enzymes of the GH31 family possess a wide range of different 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.

Glycosyl hydrolases family 31. Glycosyl hydrolases are key enzymes of carbohydrate metabolism. Family 31 comprises of enzymes that are, or similar to, alpha- galactosidases.

Alpha-glucosidase, glycosyl hydrolase family GH31 [Carbohydrate transport and metabolism].

neutral alpha-glucosidase C, neutral alpha-glucosidase AB. This subgroup includes the closely related glycosyl hydrolase family 31 (GH31) isozymes, neutral alpha-glucosidase C (GANC) and the alpha subunit of heterodimeric neutral alpha-glucosidase AB (GANAB). Initially distinguished on the basis of differences in electrophoretic mobility in starch gel, GANC and GANAB have been shown to have other differences, including those of substrate specificity. GANC and GANAB are key enzymes in glycogen metabolism that hydrolyze terminal, non-reducing 1,4-linked alpha-D-glucose residues from glycogen in the endoplasmic reticulum. The GANC/GANAB family includes the alpha-glucosidase II (ModA) from Dictyostelium discoideum as well as the alpha-glucosidase II (GLS2, or ROT2 - Reversal of TOR2 lethality protein 2) from Saccharomyces cerevisiae.

glycosyl hydrolase family 31 (GH31). GH31 enzymes 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.

ChainA, Alpha-xylosidase [Lactococcus lactis subsp. cremoris MG1363],7WJD_A Chain A, Alpha-xylosidase [Lactococcus lactis subsp. cremoris MG1363],7WJE_A Chain A, Alpha-xylosidase [Lactococcus lactis subsp. cremoris MG1363],7WJF_A Chain A, Alpha-xylosidase [Lactococcus lactis subsp. cremoris MG1363]

ChainA, Alpha-xylosidase [Lactococcus lactis subsp. cremoris MG1363],7WJ9_B Chain B, Alpha-xylosidase [Lactococcus lactis subsp. cremoris MG1363],7WJ9_C Chain C, Alpha-xylosidase [Lactococcus lactis subsp. cremoris MG1363],7WJ9_D Chain D, Alpha-xylosidase [Lactococcus lactis subsp. cremoris MG1363],7WJ9_E Chain E, Alpha-xylosidase [Lactococcus lactis subsp. cremoris MG1363],7WJ9_F Chain F, Alpha-xylosidase [Lactococcus lactis subsp. cremoris MG1363],7WJA_A Chain A, Alpha-xylosidase [Lactococcus lactis subsp. cremoris MG1363],7WJB_A Chain A, Alpha-xylosidase [Lactococcus lactis subsp. cremoris MG1363],7WLG_A Chain A, Alpha-xylosidase [Lactococcus lactis subsp. cremoris MG1363],7WLG_B Chain B, Alpha-xylosidase [Lactococcus lactis subsp. cremoris MG1363],7WLG_C Chain C, Alpha-xylosidase [Lactococcus lactis subsp. cremoris MG1363],7WLG_D Chain D, Alpha-xylosidase [Lactococcus lactis subsp. cremoris MG1363],7WLG_E Chain E, Alpha-xylosidase [Lactococcus lactis subsp. cremoris MG1363],7WLG_F Chain F, Alpha-xylosidase [Lactococcus lactis subsp. cremoris MG1363]

Crystalstructure of Family 31 alpha-glucosidase (BT_0339) from Bacteroides thetaiotaomicron [Bacteroides thetaiotaomicron VPI-5482],5F7C_B Crystal structure of Family 31 alpha-glucosidase (BT_0339) from Bacteroides thetaiotaomicron [Bacteroides thetaiotaomicron VPI-5482],5F7C_C Crystal structure of Family 31 alpha-glucosidase (BT_0339) from Bacteroides thetaiotaomicron [Bacteroides thetaiotaomicron VPI-5482],5F7C_D Crystal structure of Family 31 alpha-glucosidase (BT_0339) from Bacteroides thetaiotaomicron [Bacteroides thetaiotaomicron VPI-5482]

Crystalstructure of Paenibacillus sp. 598K alpha-1,6-glucosyltransferase [Paenibacillus sp. 598K],5X7O_B Crystal structure of Paenibacillus sp. 598K alpha-1,6-glucosyltransferase [Paenibacillus sp. 598K],5X7P_A Crystal structure of Paenibacillus sp. 598K alpha-1,6-glucosyltransferase complexed with acarbose [Paenibacillus sp. 598K],5X7P_B Crystal structure of Paenibacillus sp. 598K alpha-1,6-glucosyltransferase complexed with acarbose [Paenibacillus sp. 598K],5X7Q_A Crystal structure of Paenibacillus sp. 598K alpha-1,6-glucosyltransferase complexed with maltohexaose [Paenibacillus sp. 598K],5X7Q_B Crystal structure of Paenibacillus sp. 598K alpha-1,6-glucosyltransferase complexed with maltohexaose [Paenibacillus sp. 598K],5X7R_A Crystal structure of Paenibacillus sp. 598K alpha-1,6-glucosyltransferase complexed with isomaltohexaose [Paenibacillus sp. 598K],5X7R_B Crystal structure of Paenibacillus sp. 598K alpha-1,6-glucosyltransferase complexed with isomaltohexaose [Paenibacillus sp. 598K],5X7S_A Crystal structure of Paenibacillus sp. 598K alpha-1,6-glucosyltransferase, terbium derivative [Paenibacillus sp. 598K],5X7S_B Crystal structure of Paenibacillus sp. 598K alpha-1,6-glucosyltransferase, terbium derivative [Paenibacillus sp. 598K]

CrystalStructure of Apo Agd31B, alpha-transglucosylase in Glycoside Hydrolase Family 31 [Cellvibrio japonicus],4B9Z_A Crystal Structure of Agd31B, alpha-transglucosylase, complexed with Acarbose [Cellvibrio japonicus],4BA0_A Crystal Structure of Agd31B, alpha-transglucosylase, complexed with 5F-alpha-GlcF [Cellvibrio japonicus]

Alpha-xylosidase OS=Saccharolobus solfataricus (strain ATCC 35092 / DSM 1617 / JCM 11322 / P2) OX=273057 GN=xylS PE=1 SV=1

Alpha-glucosidase 2 OS=Bacillus thermoamyloliquefaciens OX=1425 PE=3 SV=1

Oligosaccharide 4-alpha-D-glucosyltransferase OS=Cellvibrio japonicus (strain Ueda107) OX=498211 GN=agd31B PE=1 SV=1

Alpha-xylosidase OS=Emericella nidulans (strain FGSC A4 / ATCC 38163 / CBS 112.46 / NRRL 194 / M139) OX=227321 GN=agdD PE=1 SV=1

Neutral alpha-glucosidase AB OS=Homo sapiens OX=9606 GN=GANAB PE=1 SV=3