To improve security and privacy, we are moving our web pages and services from HTTP to HTTPS. To give users of web services time to transition to HTTPS, we will support separate HTTP and HTTPS services until the end of 2017. From January 2018 most HTTP traffic will be automatically redirected to HTTPS. [more...] View this page in https
Mammalian lactase-phlorizin hydrolase (LPH) (EC 184.108.40.206 / EC 220.127.116.11).
LPH, an integral membrane glycoprotein, is the enzyme that splits lactose
in the small intestine. LPH is a large protein of about 1900 residues which
contains four tandem repeats of a domain of about 450 residues which is
evolutionary related to the above glycosyl hydrolases.
One of the conserved regions in these enzymes is centered on a conserved
glutamic acid residue which has been shown , in the β-glucosidase from
Agrobacterium, to be directly involved in glycosidic bond cleavage by acting
as a nucleophile. We have used this region as a signature pattern. As a second
signature pattern we selected a conserved region, found in the N-terminal
extremity of these enzymes, this region also contains a glutamic acid residue.
This pattern will pick up the last two domains of LPH; the first two
domains, which are removed from the LPH precursor by proteolytic processing,
have lost the active site glutamate and may therefore be inactive .
El Hassouni M., Henrissat B., Chippaux M., Barras F.
J. Bacteriol. 174:765-777(1992).
Withers S.G., Warren R.A.J., Street I.P., Rupitz K., Kempton J.B., Aebersold R.
J. Am. Chem. Soc. 112:5887-5889(1990).
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.