Melibiase. Glycoside hydrolase families GH27, GH31 and GH36 form the glycoside hydrolase clan GH-D. Glycoside hydrolase family 36 can be split into 11 families, GH36A to GH36K. This family includes enzymes from GH36A-B and GH36D-K and from GH27.

Alpha-galactosidase [Carbohydrate transport and metabolism].

glycosyl hydrolase family 36 (GH36). GH36 enzymes occur in prokaryotes, eukaryotes, and archaea with a wide range of hydrolytic activities, including alpha-galactosidase, alpha-N-acetylgalactosaminidase, stachyose synthase, and raffinose synthase. All GH36 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. GH36 members 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.

Glycosyl hydrolase family 36 N-terminal domain. This domain is found at the N-terminus of many family 36 glycoside hydrolases. It has a beta-supersandwich fold.

glycosyl hydrolase family 27 (GH27). GH27 enzymes occur in eukaryotes, prokaryotes, and archaea with a wide range of hydrolytic activities, including alpha-glucosidase (glucoamylase and sucrase-isomaltase), alpha-N-acetylgalactosaminidase, and 3-alpha-isomalto-dextranase. All GH27 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. GH27 members 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.

Crystalstructure of GH36 alpha-galactosidase AgaA from Geobacillus stearothermophilus [Geobacillus stearothermophilus],4FNR_B Crystal structure of GH36 alpha-galactosidase AgaA from Geobacillus stearothermophilus [Geobacillus stearothermophilus],4FNR_C Crystal structure of GH36 alpha-galactosidase AgaA from Geobacillus stearothermophilus [Geobacillus stearothermophilus],4FNR_D Crystal structure of GH36 alpha-galactosidase AgaA from Geobacillus stearothermophilus [Geobacillus stearothermophilus]

Crystalstructure of GH36 alpha-galactosidase AgaA A355E D548N from Geobacillus stearothermophilus in complex with raffinose [Geobacillus stearothermophilus],4FNT_B Crystal structure of GH36 alpha-galactosidase AgaA A355E D548N from Geobacillus stearothermophilus in complex with raffinose [Geobacillus stearothermophilus],4FNT_C Crystal structure of GH36 alpha-galactosidase AgaA A355E D548N from Geobacillus stearothermophilus in complex with raffinose [Geobacillus stearothermophilus],4FNT_D Crystal structure of GH36 alpha-galactosidase AgaA A355E D548N from Geobacillus stearothermophilus in complex with raffinose [Geobacillus stearothermophilus]

Crystalstructure of GH36 alpha-galactosidase AgaB from Geobacillus stearothermophilus [Geobacillus stearothermophilus]

Crystalstructure of GH36 alpha-galactosidase AgaA A355E from Geobacillus stearothermophilus [Geobacillus stearothermophilus],4FNP_B Crystal structure of GH36 alpha-galactosidase AgaA A355E from Geobacillus stearothermophilus [Geobacillus stearothermophilus],4FNP_C Crystal structure of GH36 alpha-galactosidase AgaA A355E from Geobacillus stearothermophilus [Geobacillus stearothermophilus],4FNP_D Crystal structure of GH36 alpha-galactosidase AgaA A355E from Geobacillus stearothermophilus [Geobacillus stearothermophilus],4FNS_A Crystal structure of GH36 alpha-galactosidase AgaA A355E from Geobacillus stearothermophilus in complex with 1-deoxygalactonojirimycin [Geobacillus stearothermophilus],4FNS_B Crystal structure of GH36 alpha-galactosidase AgaA A355E from Geobacillus stearothermophilus in complex with 1-deoxygalactonojirimycin [Geobacillus stearothermophilus],4FNS_C Crystal structure of GH36 alpha-galactosidase AgaA A355E from Geobacillus stearothermophilus in complex with 1-deoxygalactonojirimycin [Geobacillus stearothermophilus],4FNS_D Crystal structure of GH36 alpha-galactosidase AgaA A355E from Geobacillus stearothermophilus in complex with 1-deoxygalactonojirimycin [Geobacillus stearothermophilus]

Crystalstructure of GH36 alpha-galactosidase AgaA A355E D478A from Geobacillus stearothermophilus in complex with stachyose [Geobacillus stearothermophilus],4FNU_B Crystal structure of GH36 alpha-galactosidase AgaA A355E D478A from Geobacillus stearothermophilus in complex with stachyose [Geobacillus stearothermophilus],4FNU_C Crystal structure of GH36 alpha-galactosidase AgaA A355E D478A from Geobacillus stearothermophilus in complex with stachyose [Geobacillus stearothermophilus],4FNU_D Crystal structure of GH36 alpha-galactosidase AgaA A355E D478A from Geobacillus stearothermophilus in complex with stachyose [Geobacillus stearothermophilus]

Alpha-galactosidase AgaA OS=Geobacillus stearothermophilus OX=1422 GN=agaA PE=1 SV=1

Bifunctional alpha-galactosidase/sucrose kinase AgaSK OS=Ruminococcus gnavus OX=33038 GN=agaSK PE=1 SV=1

Alpha-galactosidase 1 OS=Pediococcus pentosaceus OX=1255 GN=agaR PE=3 SV=1

Alpha-galactosidase Mel36A OS=Lactobacillus acidophilus (strain ATCC 700396 / NCK56 / N2 / NCFM) OX=272621 GN=melA PE=1 SV=1

Probable alpha-galactosidase G OS=Aspergillus terreus (strain NIH 2624 / FGSC A1156) OX=341663 GN=aglG PE=3 SV=1