Ubiquinol oxidase subunit III domain (IPR033946)

Short name: Ubiquinol_oxase_su3_dom

Overlapping homologous superfamilies

Domain relationships


Ubiquinol oxidase is a multi-chain transmembrane protein located in the cell membrane and one of several aerobic bacterial terminal oxidases [PMID: 7575098]. This complex couples oxidation of reduced quinones to the reduction of molecular oxygen to water, and the pumping of protons to form the proton gradient utilised for ATP production. aa3-type oxidases contain two haem A cofactors as well as copper atoms at the active site.

Quinone oxidases feature four subunits in contrast to the 13 subunit bovine cytochrome c oxidase (CcO). Subunits I, II and III of ubiquinol oxidase are homologous to the corresponding subunits in bovine CcO [PMID: 8392948, PMID: 8253216]. Although not required for catalytic activity, subunit III appears to be involved in assembly of the multimer complex [PMID: 11017202].

This entry represents a domain found in ubiquinol oxidase subunit III. While this signature predominantly matches the ubiquinol oxidase version of the domain, it also includes some cytochrome c oxidase homologues.

Contributing signatures

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