PROSITE documentation PDOC00443

Alpha-galactosidase signature




Description

α-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). α-galactosidase is present in a variety of organisms. There is a considerable degree of similarity in the sequence of α-galactosidase from various eukaryotic species.

Escherichia coli α-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 α-galactosidase (gene rafA) [2] contains a region of about 50 amino acids which is similar to a domain of the eukaryotic α-galactosidases.

α-N-acetylgalactosaminidase (EC 3.2.1.49) [3] catalyzes the hydrolysis of terminal non-reducing N-acetyl-D-galactosamine residues in N-acetyl-α-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 α-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.

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.

Last update:

December 2004 / Pattern and text revised.

Technical section

PROSITE method (with tools and information) covered by this documentation:

ALPHA_GALACTOSIDASE, PS00512; Alpha-galactosidase signature  (PATTERN)


References

1AuthorsDey P.M., Pridham J.B.C.
TitleBiochemistry of -galactosidases.
SourceAdv. Enzymol. 36:91-130(1972).
PubMed ID4561015

2AuthorsAslanidis C., Schmid K., Schmitt R.
TitleNucleotide sequences and operon structure of plasmid-borne genes mediating uptake and utilization of raffinose in Escherichia coli.
SourceJ. Bacteriol. 171:6753-6763(1989).
PubMed ID2556373

3AuthorsWang A.M., Bishop D.F., Desnick R.J.
TitleHuman 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.
SourceJ. Biol. Chem. 265:21859-21866(1990).
PubMed ID2174888

4AuthorsHenrissat B.
TitleA classification of glycosyl hydrolases based on amino acid sequence similarities.
SourceBiochem. J. 280:309-316(1991).
PubMed ID1747104

E1Sourcehttp://www.uniprot.org/docs/glycosid



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