Binding Site

Aromatic-ring-hydroxylating dioxygenase, 2Fe-2S-binding site (IPR015881)

Short name: Ring-hydroxy_dOase_2Fe2S_BS


Aromatic ring hydroxylating dioxygenases are multicomponent 1,2-dioxygenase complexes that convert closed-ring structures to non-aromatic cis-diols [PMID: 1885518]. The complex has both hydroxylase and electron transfer components. The hydroxylase component is itself composed of two subunits: an alpha-subunit of about 50 kDa, and a beta-subunit of about 20 kDa. The electron transfer component is either composed of two subunits: a ferredoxin and a ferredoxin reductase or by a single bifunctional ferredoxin/reductase subunit. Sequence analysis of hydroxylase subunits of ring hydroxylating systems (including toluene, benzene and napthalene 1,2-dioxygenases) suggests they are derived from a common ancestor [PMID: 1885518]. The alpha-subunit binds both a Rieske-like 2Fe-2S cluster and an iron atom: conserved Cys and His residues in the N-terminal region may provide 2Fe-2S ligands, while conserved His and Tyr residues may coordinate the iron. The beta subunit may be responsible for the substrate specificity of the dioxygenase system [PMID: 1885518].

The alpha-subunit of the hydroxylase components bind both a 2Fe-2S type iron-sulphur centre and an iron atom. There is, in the N-terminal section of these proteins, a conserved region of 24 residues which contains two cysteines and two histidines which have been shown to be involved in the binding of the iron-sulphur centre [PMID: 9634695].

GO terms

Biological Process

GO:0055114 oxidation-reduction process

Molecular Function

GO:0051537 2 iron, 2 sulfur cluster binding
GO:0005506 iron ion binding
GO:0016705 oxidoreductase activity, acting on paired donors, with incorporation or reduction of molecular oxygen

Cellular Component

No terms assigned in this category.

Contributing signatures

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