Binding Site

Oxidoreductase, molybdopterin binding site (IPR022407)

Short name: OxRdtase_Mopterin_BS


This entry represents a motif surrounding a cysteine residue that could be involved in binding the molybdopterin cofactor.

A number of different eukaryotic oxidoreductases that require and bind a molybdopterin cofactor have been shown [PMID: 2015248] to share a few regions of sequence similarity. These enzymes include xanthine dehydrogenase (EC:, aldehyde oxidase (EC:, nitrate reductase (EC:, and sulphite oxidase (EC: The multidomain redox enzyme NAD(P)H:nitrate reductase (NR) catalyses the reduction of nitrate to nitrite in a single polypeptide electron transport chain with electron flow from NAD(P)H-FAD-cytochrome b5-molybdopterin-NO(3). Three forms of NR are known, an NADH-specific enzyme found in higher plants and algae (EC:; an NAD(P)H-bispecific enzyme found in higher plants, algae and fungi (EC:; and an NADPH-specific enzyme found only in fungi (EC: [PMID: 2204158]. The mitochondrial enzyme sulphite oxidase (sulphite:ferricytochrome c oxidoreductase; EC: catalyses oxidation of sulphite to sulphate, using cytochrome c as the physiological electron acceptor. Sulphite oxidase consists of two structure/function domains, an N-terminal haem domain, similar to cytochrome b5; and a C-terminal molybdopterin domain [PMID: 9428520].

GO terms

Biological Process

GO:0055114 oxidation-reduction process

Molecular Function

GO:0043546 molybdopterin cofactor binding

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
PROSITE patterns