{PDOC00531}
{PS00719; GLYCOSYL_HYDROL_F2_1}
{PS00608; GLYCOSYL_HYDROL_F2_2}
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* Glycosyl hydrolases family 2 signatures *
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It has  been shown [1,2,E1] 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)-[LIVMFYWS](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: [DENQLF]-[KRVW]-N-[HRY]-[STAPV]-[SAC]-[LIVMFS]-[LIVMFSA]-
                    [LIVMFS]-W-[GSV]-x(2,3)-N-E
                    [E is the active site residue]
-Sequences known to belong to this class detected by the pattern: ALL,  except
 for Rhizobium meliloti lacZ.
-Other sequence(s) detected in Swiss-Prot: NONE.

-Expert(s) to contact by email:
           Henrissat B.; bernie@afmb.cnrs-mrs.fr

-Last update: April 2006 / Pattern revised.

[ 1] Henrissat B.
     "A classification of glycosyl hydrolases based on amino acid sequence
     similarities."
     Biochem. J. 280:309-316(1991).
     PubMed=1747104
[ 2] Schroeder C.J., Robert C., Lenzen G., McKay L.L., Mercenier A.
     "Analysis of the lacZ sequences from two Streptococcus thermophilus
     strains: comparison with the Escherichia coli and Lactobacillus
     bulgaricus beta-galactosidase sequences."
     J. Gen. Microbiol. 137:369-380(1991).
     PubMed=1901904
[ 3] Gebler J.C., Aebersold R., Withers S.G.
     "Glu-537, not Glu-461, is the nucleophile in the active site of (lac
     Z) beta-galactosidase from Escherichia coli."
     J. Biol. Chem. 267:11126-11130(1992).
     PubMed=1350782
[E1] https://www.uniprot.org/docs/glycosid

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