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- *********************************
- * Alpha-galactosidase signature *
- *********************************
-
- Alpha-galactosidase (EC 3.2.1.22) (melibiase) [1] 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) [2] 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) [3] 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.
-
- We selected, as a signature pattern for these enzymes, the N-terminal part of
- the conserved domain. The pattern contains two conserved aspartic acid
- residues which could be involved in the catalytic mechanism.
-
- -Consensus pattern: G-[LIVMFY]-x(2)-[LIVMFY]-x-[LIVM]-D-D-x-W-x(3,4)-R-[DNS]
- -Sequences known to belong to this class detected by the pattern: ALL.
- -Other sequence(s) detected in SWISS-PROT: NONE.
-
- -Note: these proteins belong to family 27 in the classification of glycosyl
- hydrolases [4].
-
- -Expert(s) to contact by email: Henrissat B.
- bernie@cermav.grenet.fr
-
- -Last update: December 1992 / Pattern and text revised.
-
- [ 1] Dey P.M., Pridham J.B.C.
- Adv. Enzymol. 36:91-120(1972).
- [ 2] Aslanidis C., Schmid K., Schmitt R.
- J. Bacteriol. 171:6753-6763(1989).
- [ 3] Wang A.M., Bishop D.F., Desnick R.J.
- J. Biol. Chem. 265:21859-21866(1990).
- [ 4] Henrissat B.
- Biochem. J. 280:309-316(1991).
-