{PDOC00443} {PS00512; ALPHA_GALACTOSIDASE} {BEGIN} ********************************* * 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-[DF]-x(1,2)-W-x(3,7)- [RV]-[DNSF] -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 families 27 and 36 in the classification of glycosyl hydrolases [4,E1]. -Expert(s) to contact by email: Henrissat B.; bernie@afmb.cnrs-mrs.fr -Last update: December 2004 / Pattern and text revised. [ 1] Dey P.M., Pridham J.B.C. "Biochemistry of -galactosidases." Adv. Enzymol. 36:91-130(1972). PubMed=4561015 [ 2] Aslanidis C., Schmid K., Schmitt R. "Nucleotide sequences and operon structure of plasmid-borne genes mediating uptake and utilization of raffinose in Escherichia coli." J. Bacteriol. 171:6753-6763(1989). PubMed=2556373 [ 3] Wang A.M., Bishop D.F., Desnick R.J. "Human alpha-N-acetylgalactosaminidase-molecular cloning, nucleotide sequence, and expression of a full-length cDNA. Homology with human alpha-galactosidase A suggests evolution from a common ancestral gene." J. Biol. Chem. 265:21859-21866(1990). PubMed=2174888 [ 4] Henrissat B. "A classification of glycosyl hydrolases based on amino acid sequence similarities." Biochem. J. 280:309-316(1991). PubMed=1747104 [E1] https://www.uniprot.org/docs/glycosid -------------------------------------------------------------------------------- PROSITE is copyrighted by the SIB Swiss Institute of Bioinformatics and distributed under the Creative Commons Attribution-NonCommercial-NoDerivatives (CC BY-NC-ND 4.0) License, see https://prosite.expasy.org/prosite_license.html -------------------------------------------------------------------------------- {END}