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- *******************************************
- * Glycosyl hydrolases family 2 signatures *
- *******************************************
-
- It has been shown [1,2] that the following glycosyl hydrolases can be, on the
- basis of sequence similarities, classified into a single family:
-
- - Beta-galactosidases (EC 3.2.1.23) from bacteria such as Escherichia coli
- (genes lacZ and ebgA), Clostridium acetobutylicum, Clostridium
- thermosulfurogenes, Klebsiella pneumoniae, Lactobacillus delbrueckii, or
- Streptococcus thermophilus and from the fungi Kluyveromyces lactis.
- - Beta-glucuronidase (EC 3.2.1.31) from Escherichia coli (gene uidA) and from
- mammals.
-
- One of the conserved regions in these enzymes is centered on a conserved
- glutamic acid residue which has been shown [3], in Escherichia coli lacZ, to
- be the general acid/base catalyst in the active site of the enzyme. We have
- used this region as a signature pattern. As a second signature pattern we
- selected a highly conserved region located some sixty residues upstream from
- the active site glutamate.
-
- -Consensus pattern: N-x-[LIVMFYWD]-R-[STACN](2)-H-Y-P-x(4)-[LIVMFYW](2)-x(3)-
- [DN]-x(2)-G-[LIVMFYW](4)
- -Sequences known to belong to this class detected by the pattern: ALL.
- -Other sequence(s) detected in SWISS-PROT: NONE.
-
- -Consensus pattern: [DENQF]-[KRVW]-N-H-[AP]-[SAC]-[LIVMF](3)-W-[GS]-x(2,3)-N-E
- [E is the active site residue]
- -Sequences known to belong to this class detected by the pattern: ALL.
- -Other sequence(s) detected in SWISS-PROT: NONE.
-
- -Expert(s) to contact by email: Henrissat B.
- bernie@cermav.grenet.fr
-
- -Last update: October 1993 / Patterns and text revised.
-
- [ 1] Henrissat B.
- Biochem. J. 280:309-316(1991).
- [ 2] Schroeder C.J., Robert C., Lenzen G., McKay L.L., Mercenier A.
- J. Gen. Microbiol. 137:369-380(1991).
- [ 3] Gebler J.C., Aebersold R., Withers S.G.
- J. Biol. Chem. 267:11126-11130(1992).
-