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.

Exonuclease-Endonuclease-Phosphatase domain; uncharacterized family 1. This family of uncharacterized proteins belongs to a superfamily that includes the catalytic domain (exonuclease/endonuclease/phosphatase, EEP, domain) of a diverse set of proteins including the ExoIII family of apurinic/apyrimidinic (AP) endonucleases, inositol polyphosphate 5-phosphatases (INPP5), neutral sphingomyelinases (nSMases), deadenylases (such as the vertebrate circadian-clock regulated nocturnin), bacterial cytolethal distending toxin B (CdtB), deoxyribonuclease 1 (DNase1), the endonuclease domain of the non-LTR retrotransposon LINE-1, and related domains. These diverse enzymes share a common catalytic mechanism of cleaving phosphodiester bonds. Their substrates range from nucleic acids to phospholipids and perhaps, proteins.

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

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],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]

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]

Bacteroidesthetaiotaomicron VPI-5482 mannosyl-6-phosphatase Bt3783 [Bacteroides thetaiotaomicron VPI-5482],4C1R_B Bacteroides thetaiotaomicron VPI-5482 mannosyl-6-phosphatase Bt3783 [Bacteroides thetaiotaomicron VPI-5482],4C1R_C Bacteroides thetaiotaomicron VPI-5482 mannosyl-6-phosphatase Bt3783 [Bacteroides thetaiotaomicron VPI-5482],4C1R_D Bacteroides thetaiotaomicron VPI-5482 mannosyl-6-phosphatase Bt3783 [Bacteroides thetaiotaomicron VPI-5482]

CrystalStructure of endonuclease/exonuclease/phosphatase family protein from Bacteroides thetaiotaomicron, Northeast Structural Genomics Consortium Target BtR318A [Bacteroides thetaiotaomicron],3MPR_B Crystal Structure of endonuclease/exonuclease/phosphatase family protein from Bacteroides thetaiotaomicron, Northeast Structural Genomics Consortium Target BtR318A [Bacteroides thetaiotaomicron],3MPR_C Crystal Structure of endonuclease/exonuclease/phosphatase family protein from Bacteroides thetaiotaomicron, Northeast Structural Genomics Consortium Target BtR318A [Bacteroides thetaiotaomicron],3MPR_D Crystal Structure of endonuclease/exonuclease/phosphatase family protein from Bacteroides thetaiotaomicron, Northeast Structural Genomics Consortium Target BtR318A [Bacteroides thetaiotaomicron]

ChainA, Putative endonuclease/exonuclease/phosphatase family protein [Phocaeicola vulgatus ATCC 8482]

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

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

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

Neutral alpha-glucosidase C (Fragment) OS=Macaca fascicularis OX=9541 GN=GANC PE=2 SV=2

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