β-galactosidases (EC 126.96.36.199) 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 , probably acts as the proton donor in the catalytic mechanism.
We use this region as a signature pattern.
PROSITE is copyright. It is produced by the SIB Swiss Institute
Bioinformatics. There are no restrictions on its use by non-profit
institutions as long as its content is in no way modified. Usage by and
for commercial entities requires a license agreement. For information
about the licensing scheme send an email to
or see: prosite_license.html.