| Type: | Conserved_site | Name: | Glycoside hydrolase family 27/36, conserved site |
| Description: | 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 [, ]. This classification is available on the CAZy (CArbohydrate-Active EnZymes) web site. Families 27 () and 36 () encompasses alpha-galactosidases and alpha-N-acetylgalactosaminidases.Alpha-galactosidase (EC 3.2.1.22) (melibiase) [] catalyses 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 (EC 3.2.1.49) [] catalyses 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 entry represents a conserved site in families 27 and 36. It contains two conserved aspartic acid residues which could be involved in the catalytic mechanism. | Short Name: | Glyco_hydro_27/36_CS |
