Glycoside hydrolase family 36 (IPR002252)

Short name: Glyco_hydro_36

Overlapping homologous superfamilies

Family relationships



O-Glycosyl hydrolases (EC:3.2.1.) are a widespread group of enzymes that hydrolyse the glycosidic bond between two or more carbohydrates, or between a carbohydrate and a non-carbohydrate moiety. A classification system for glycosyl hydrolases, based on sequence similarity, has led to the definition of 85 different families [PMID: 7624375, PMID: 8535779]. This classification is available on the CAZy (CArbohydrate-Active EnZymes) web site.

Glycoside hydrolase family 36 (GH36) occur in prokaryotes, eukaryotes, and archaea with a wide range of hydrolytic activities, including alpha-galactosidase, alpha-N-acetylgalactosaminidase, stachyose synthase, and raffinose synthase [PMID: 12123797, PMID: 20681989]. 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 [PMID: 20681989]. Two aspartic acid residues have been identified as the catalytic nucleophile and the acid/base, respectively.

Proteins in this entry also include AgaSK, a bifunctional protein that contains two domains: one closely related to alpha-galactosidases from glycoside hydrolase family GH36 and the other containing a nucleotide-binding motif. It can hydrolyze melibiose and raffinose to galactose and either glucose or sucrose, respectively, and can specifically phosphorylate sucrose on the C6 position of glucose in the presence of ATP [PMID: 21931163].

GO terms

Biological Process

GO:0005975 carbohydrate metabolic process

Molecular Function

GO:0004557 alpha-galactosidase activity

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.