home *** CD-ROM | disk | FTP | other *** search
- ******************************************************
- * Eukaryotic molybdopterin oxidoreductases signature *
- ******************************************************
-
- A number of different eukaryotic oxidoreductases that require and bind a
- molybdopterin cofactor have been shown [1] to share a few regions of sequence
- similarity. These enzymes are:
-
- - Xanthine dehydrogenase (EC 1.1.1.204), 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 iron-sulfur binding domain, a central
- FAD/NAD-binding domain and a C-terminal Mo-pterin domain.
- - Nitrate reductase (EC 1.6.6.1), 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 and a C-terminal FAD/NAD-binding cytochrome reductase domain.
- - Sulfite oxidase (EC 1.8.3.1), 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 molybdoterin cofactor.
-
- -Consensus pattern: [GA]-x(3)-[KRNQH]-x(11,14)-[LIVMFYWS]-x(8)-[LIVM]-x-C-
- x(2)-[DEN]-R-x(2)-[DE]
- -Sequences known to belong to this class detected by the pattern: ALL.
- -Other sequence(s) detected in SWISS-PROT: 3.
- -Last update: June 1994 / Pattern and text revised.
-
- [ 1] Wooton J.C., Nicolson R.E., Cock J.M., Walters D.E., Burke J.F.,
- Doyle W.A., Bray R.C.
- Biochim. Biophys. Acta 1057:157-185(1991).
-