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.

Alpha-galactosidase [Carbohydrate transport and metabolism].

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.

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.

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.

Structureof apo structure of GH36 alpha-galactosidase from Thermotoga maritima [Thermotoga maritima],5M12_A Structure of GH36 alpha-galactosidase from Thermotoga maritima in complex with intact cyclopropyl-carbasugar. [Thermotoga maritima],5M16_A Structure of GH36 alpha-galactosidase from Thermotoga maritima in complex with a hydrolysed cyclopropyl carbasugar. [Thermotoga maritima],5M1I_A Structure of GH36 alpha-galactosidase from Thermotoga maritima in a covalent complex with a cyclopropyl carbasugar. [Thermotoga maritima],6GVD_A Alpha-galactosidase from Thermotoga maritima in complex with cyclohexene-based carbasugar mimic of galactose [Thermotoga maritima MSB8],6GWG_A Alpha-galactosidase from Thermotoga maritima in complex with cyclohexene-based carbasugar mimic of galactose covalently linked to the nucleophile [Thermotoga maritima MSB8],6GX8_A Alpha-galactosidase from Thermotoga maritima in complex with hydrolysed cyclohexene-based carbasugar mimic of galactose [Thermotoga maritima MSB8]

Crystalstructure of Alpha-galactosidase (EC 3.2.1.22) (Melibiase) (tm1192) from Thermotoga maritima at 2.34 A resolution [Thermotoga maritima]

Alpha-galactosidasemutant D378A from Thermotoga maritima in complex with intact cyclohexene-based carbasugar mimic of galactose with 3,5 difluorophenyl leaving group [Thermotoga maritima MSB8],6GWF_A Alpha-galactosidase mutant D387A from Thermotoga maritima in complex with intact cyclohexene-based carbasugar mimic of galactose with 2,4-dinitro leaving group [Thermotoga maritima MSB8]

TtGalA,alpha-galactosidase from Thermus thermopilus in apo form [Thermus thermophilus HB8],6LCJ_B TtGalA, alpha-galactosidase from Thermus thermopilus in apo form [Thermus thermophilus HB8],6LCJ_C TtGalA, alpha-galactosidase from Thermus thermopilus in apo form [Thermus thermophilus HB8],6LCJ_D TtGalA, alpha-galactosidase from Thermus thermopilus in apo form [Thermus thermophilus HB8],6LCJ_E TtGalA, alpha-galactosidase from Thermus thermopilus in apo form [Thermus thermophilus HB8],6LCJ_F TtGalA, alpha-galactosidase from Thermus thermopilus in apo form [Thermus thermophilus HB8],6LCK_A TtGalA, alpha-galactosidase from Thermus thermophilus in complex with p-nitrophenyl alpha-D-galactopyranoside (alpha-NPG) [Thermus thermophilus HB8],6LCK_B TtGalA, alpha-galactosidase from Thermus thermophilus in complex with p-nitrophenyl alpha-D-galactopyranoside (alpha-NPG) [Thermus thermophilus HB8],6LCK_C TtGalA, alpha-galactosidase from Thermus thermophilus in complex with p-nitrophenyl alpha-D-galactopyranoside (alpha-NPG) [Thermus thermophilus HB8],6LCL_A TtGalA, alpha-galactosidase from Thermus thermophilus in complex with stachyose [Thermus thermophilus HB8],6LCL_C TtGalA, alpha-galactosidase from Thermus thermophilus in complex with stachyose [Thermus thermophilus HB8],6LCL_E TtGalA, alpha-galactosidase from Thermus thermophilus in complex with stachyose [Thermus thermophilus HB8]

ChainA, Alpha-galactosidase [Levilactobacillus brevis ATCC 367],3MI6_B Chain B, Alpha-galactosidase [Levilactobacillus brevis ATCC 367],3MI6_C Chain C, Alpha-galactosidase [Levilactobacillus brevis ATCC 367],3MI6_D Chain D, Alpha-galactosidase [Levilactobacillus brevis ATCC 367]

Alpha-galactosidase OS=Thermotoga maritima (strain ATCC 43589 / DSM 3109 / JCM 10099 / NBRC 100826 / MSB8) OX=243274 GN=galA PE=1 SV=1

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

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

Probable alpha-galactosidase C OS=Aspergillus oryzae (strain ATCC 42149 / RIB 40) OX=510516 GN=aglC PE=3 SV=1