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].

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-xylosidase YicI-like. YicI alpha-xylosidase is a glycosyl hydrolase family 31 (GH31) enzyme that catalyzes the release of an alpha-xylosyl residue from the non-reducing end of alpha-xyloside substrates such as alpha-xylosyl fluoride and isoprimeverose. YicI forms a homohexamer (a trimer of dimers). 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. The YicI family corresponds to subgroup 4 in the Ernst et al classification of GH31 enzymes.

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.

Structureof alpha-galactosidase from Lactobacillus acidophilus NCFM, PtCl4 derivative [Lactobacillus acidophilus NCFM],2XN0_B Structure of alpha-galactosidase from Lactobacillus acidophilus NCFM, PtCl4 derivative [Lactobacillus acidophilus NCFM],2XN1_A Structure of alpha-galactosidase from Lactobacillus acidophilus NCFM with TRIS [Lactobacillus acidophilus NCFM],2XN1_B Structure of alpha-galactosidase from Lactobacillus acidophilus NCFM with TRIS [Lactobacillus acidophilus NCFM],2XN1_C Structure of alpha-galactosidase from Lactobacillus acidophilus NCFM with TRIS [Lactobacillus acidophilus NCFM],2XN1_D Structure of alpha-galactosidase from Lactobacillus acidophilus NCFM with TRIS [Lactobacillus acidophilus NCFM]

Structureof alpha-galactosidase from Lactobacillus acidophilus NCFM with galactose [Lactobacillus acidophilus NCFM]

SpAgawild type apo structure [Streptococcus pneumoniae TIGR4],6PHV_A Chain A, Alpha-galactosidase [Streptococcus pneumoniae TIGR4]

ChainA, Alpha-galactosidase [Streptococcus pneumoniae TIGR4],6PHX_A SpAga D472N structure in complex with raffinose [Streptococcus pneumoniae TIGR4],6PHY_A Chain A, Alpha-galactosidase [Streptococcus pneumoniae TIGR4],6PI0_A AgaD472N-Linear Blood group B type 2 trisaccharide complex structure [Streptococcus pneumoniae TIGR4]

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]

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

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

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

Alpha-galactosidase OS=Escherichia coli OX=562 GN=rafA 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