PROSITE documentation PDOC00910
Glycosyl hydrolases family 35 putative active site


β-galactosidases (EC from mammals, fungi, plants and the bacteria Xanthomonas manihotis are evolutionary related [1,2]. They belong to family 35 in the classification of glycosyl hydrolases [3,E1].

Mammalian β-galactosidase is a lysosomal enzyme (gene GLB1) which cleaves the terminal galactose from gangliosides, glycoproteins, and glycosaminoglycans and whose deficiency is the cause of the genetic disease Gm(1) gangliosidosis (Morquio disease type B).

On of the best conserved regions in these enzymes contains a glutamic acid residue which, on the basis of similarities with other families of glycosyl hydrolases [4], probably acts as the proton donor in the catalytic mechanism. We use this region as a signature pattern.

Expert(s) to contact by email:

Henrissat B.

Last update:

May 2004 / Text revised.


Technical section

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

GLYCOSYL_HYDROL_F35, PS01182; Glycosyl hydrolases family 35 putative active site  (PATTERN)


1AuthorsTaron C.H. Benner J.S. Hornstra L.J. Guthrie E.P.
TitleA novel beta-galactosidase gene isolated from the bacterium Xanthomonas manihotis exhibits strong homology to several eukaryotic beta-galactosidases.
SourceGlycobiology 5:603-610(1995).
PubMed ID8563148

2AuthorsCarey A.T. Holt K. Picard S. Wilde R. Tucker G.A. Bird C.R. Schuch W. Seymour G.B.
TitleTomato exo-(1-->4)-beta-D-galactanase. Isolation, changes during ripening in normal and mutant tomato fruit, and characterization of a related cDNA clone.
SourcePlant Physiol. 108:1099-1107(1995).
PubMed ID7630937

3AuthorsHenrissat B. Bairoch A.
TitleNew families in the classification of glycosyl hydrolases based on amino acid sequence similarities.
SourceBiochem. J. 293:781-788(1993).
PubMed ID8352747

4AuthorsHenrissat B. Callebaut I. Fabrega S. Lehn P. Mornon J.-P. Davies G.
TitleConserved catalytic machinery and the prediction of a common fold for several families of glycosyl hydrolases.
SourceProc. Natl. Acad. Sci. U.S.A. 92:7090-7094(1995).
PubMed ID7624375


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