| Literature References | 1. HENRISSAT, B. AND BAIROCH, A.
New families in the classification of glycosyl hydrolases based on amino
acid sequence similarities.
BIOCHEM.J. 293 781-788 (1993).
2. HENRISSAT, B.
A classification of glycosyl hydrolases based on amino acid sequence
similarities.
BIOCHEM.J. 280 309-316 (1991).
3. DAVIES, G. AND HENRISSAT, B.
Structures and mechanisms of glycosyl hydrolases.
STRUCTURE 3 853-859 (1995).
4. HENRISSAT, B. AND BAIROCH, A.
Updating the sequence-based classification of glycosyl hydrolases.
BIOCHEM.J. 316 695-696 (1996).
5. TARON, C.H., BENNER, J.S., HORNSTRA, L.J. AND GUTHRIE, E.P.
A novel beta-galactosidase gene isolated from the bacterium Xanthomonas
manihotis exhibits strong homology to several eukaryotic beta-galactosidases.
GLYCOBIOLOGY 5 603-610 (1995).
6. CAREY, A.T., HOLT, K., PICARD, S., WILDE, R., TUCKER, G.A., BIRD, C.R.,
SCHUCH, W. AND SEYMOUR, G.B.
Tomato exo-(1-]4)-beta-d-galactanase - isolation, changes during ripening
in normal and mutant tomato fruit, and characterization of a related
cDNA clone.
PLANT PHYSIOL. 108 1099-1107 (1995).
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| Documentation | O-Glycosyl hydrolases (EC 3.2.1.-) are a widespread group of enzymes that
hydrolyse the glycosidic bond between two or more carbohydrates, or between
a carbohydrate and a non-carbohydrate moiety. A classification system for
glycosyl hydrolases, based on sequence similarity, has led to the definition
of up to 60 different families [1-4] (http://expasy.hcuge.ch/cgi-bin/lists?
glycosid.txt). Family 35 encompasses beta-galactosidases [5,6].
Mammalian beta-galactosidase is a lysosomal enzyme that cleaves the terminal
galactose from gangliosides, glycoproteins and glycosaminoglycans.
Deficiency in the enzyme results in the genetic disease Gm(1) gangliosidosis
(Morquio disease type B).
GLHYDRLASE35 is a 9-element fingerprint that provides a signature for
family 35 glycosyl hydrolases. The fingerprint was derived from an initial
alignment of 9 sequences: the motifs were drawn from conserved regions
spanning the central portion of the alignment - motif 4 includes the region
encoded by PROSITE pattern GLYCOSYL_HYDROL_F35 (PS01182), which contains a
conserved Glu residue that may act as the proton donor in the catalytic
mechanism. Two iterations on OWL29.3 were required to reach convergence, at
which point a true set comprising 10 sequences was identified. Several
partial matches were also found, all of which are related sequences that
fail to make significant matches with one or more motifs.
An update on SPTR37_9f identified a true set of 17 sequences, and 8
partial matches.
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