Due to improvement work scheduled on this server, some services may not be fully operational on Tuesday December 12 daytime (CEST).
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
A number of different eukaryotic oxidoreductases that require and bind a
molybdopterin cofactor have been shown  to share a few regions of sequence
similarity. These enzymes are:
Xanthine dehydrogenase (EC 22.214.171.124), which catalyzes the oxidation of
xanthine to uric acid with the concomitant reduction of NAD. Structurally,
this enzyme of about 1300 amino acids consists of at least three distinct
domains: an N-terminal 2Fe-2S ferredoxin-like iron-sulfur binding domain
(see <PDOC00175>), a central FAD/NAD-binding domain and a C-terminal Mo-
Aldehyde oxidase (EC 126.96.36.199), which catalyzes the oxidation aldehydes into
acids. Aldehyde oxidase is highly similar to xanthine dehydrogenase in its
sequence and domain structure.
Nitrate reductase (EC 188.8.131.52), which catalyzes the reduction of nitrate
to nitrite. Structurally, this enzyme of about 900 amino acids consists of
an N-terminal Mo-pterin domain, a central cytochrome b5-type heme-binding
domain (see <PDOC00170>) and a C-terminal FAD/NAD-binding cytochrome
Sulfite oxidase (EC 184.108.40.206), which catalyzes the oxidation of sulfite to
sulfate. Structurally, this enzyme of about 460 amino acids consists of an
N-terminal cytochrome b5-binding domain followed by a Mo-pterin domain.
There are a few conserved regions in the sequence of the molybdopterin-binding
domain of these enzymes. The pattern we use to detect these proteins is based
on one of them. It contains a cysteine residue which could be involved in
binding the molybdopterin cofactor.
April 2006 / Pattern revised.
PROSITE method (with tools and information) covered by this documentation:
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.