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.

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 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.

Glycoside hydrolases, clan D. This group of glycosyl hydrolase families is comprised of glycosyl hydrolase family 31 (GH31), family 36 (GH36), and family 27 (GH27). These structurally and mechanistically related protein families 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. They have a wide range of functions including alpha-glucosidase, alpha-xylosidase, 6-alpha-glucosyltransferase, 3-alpha-isomaltosyltransferase, alpha-N-acetylgalactosaminidase, stachyose synthase, raffinose synthase, and alpha-1,4-glucan lyase.

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 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 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

Alpha-galactosidase 2 OS=Pediococcus pentosaceus OX=1255 GN=agaS PE=3 SV=1

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

Probable alpha-galactosidase G OS=Emericella nidulans (strain FGSC A4 / ATCC 38163 / CBS 112.46 / NRRL 194 / M139) OX=227321 GN=aglG PE=2 SV=1

Probable alpha-galactosidase C OS=Aspergillus flavus (strain ATCC 200026 / FGSC A1120 / IAM 13836 / NRRL 3357 / JCM 12722 / SRRC 167) OX=332952 GN=aglC PE=3 SV=2