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In molecular biology, glycoside hydrolase family 36 is a family of glycoside hydrolases. Glycoside hydrolases 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 glycoside hydrolases, based on sequence similarity, has led to the definition of >100 different families.〔(Bairoch, A. "Classification of glycosyl hydrolase families and index of glycosyl hydrolase entries in SWISS-PROT". 1999. )〕 This classification is available on the CAZy(http://www.cazy.org/GH1.html) web site,〔(Henrissat, B. and Coutinho P.M. "Carbohydrate-Active Enzymes server". 1999. )〕 and also discussed at CAZypedia, an online encyclopedia of carbohydrate active enzymes.〔(CAZypedia, an online encyclopedia of carbohydrate-active enzymes. )〕 Glycoside hydrolase family 36 together with family 31 and family 27 alpha-galactosidases form the glycosyl hydrolase clan GH-D ((CAZY GH )), a superfamily of alpha-galactosidases, alpha-N-acetylgalactosaminidases, and isomaltodextranases which are likely to share a common catalytic mechanism and structural topology. Alpha-galactosidase () (melibiase) catalyzes the hydrolysis of melibiose into galactose and glucose. In man, the deficiency of this enzyme is the cause of Fabry's disease (X-linked sphingolipidosis). Alpha-galactosidase is present in a variety of organisms. There is a considerable degree of similarity in the sequence of alpha-galactosidase from various eukaryotic species. ''Escherichia coli'' alpha-galactosidase (gene melA), which requires NAD and magnesium as cofactors, is not structurally related to the eukaryotic enzymes; by contrast, an ''Escherichia coli'' plasmid encoded alpha-galactosidase (gene rafA ) contains a region of about 50 amino acids which is similar to a domain of the eukaryotic alpha-galactosidases. Alpha-N-acetylgalactosaminidase () catalyzes the hydrolysis of terminal non-reducing N-acetyl-D-galactosamine residues in N-acetyl-alpha-D- galactosaminides. In man, the deficiency of this enzyme is the cause of Schindler and Kanzaki diseases. The sequence of this enzyme is highly related to that of the eukaryotic alpha-galactosidases. This family also includes raffinose synthase proteins, also known as seed inhibition (Sip1) proteins. Raffinose (O-alpha- D-galactopyranosyl- (1-->6)- O-alpha- D-glucopyranosyl-(1<-->2)- O-beta- D-fructofuranoside) is a widespread oligosaccharide in plant seeds and other tissues. Raffinose synthase is the key enzyme that channels sucrose into the raffinose oligosaccharide pathway. Glycoside hydrolase family 36 also includes enzymes with α-N-acetylgalactosaminidase and stachyose synthase activities. Glycoside hydrolase family 36 can be subdivided into 11 families, GH36A to GH36K. ==References== 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Glycoside hydrolase family 36」の詳細全文を読む スポンサード リンク
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