Cytochrome c oxidase, monohaem subunit/FixO (IPR003468)

Short name: Cyt_c_oxidase_monohaem-su/FixO

Overlapping homologous superfamilies

Family relationships



Cytochrome cbb3 oxidases are found almost exclusively in Proteobacteria, and represent a distinctive class of proton-pumping respiratory haem-copper oxidases (HCO) that lack many of the key structural features that contribute to the reaction cycle of the intensely studied mitochondrial cytochrome c oxidase (CcO) [PMID: 15100055]. Cytochrome cbb3 oxidases are required both to support symbiotic nitrogen fixation, whilst ensuring that the oxygen-labile nitrogenase is not compromised. Cytochrome cbb3 oxidases consist of four subunits: FixN (or CcoN), FixO (or CcoO), FixP (or CcoP) and FixQ (or CcoQ). The catalytic core is comprised of subunits FixN, FixO and FixP, where FixN acts as the catalytic subunit, and Fix O and FixP are membrane-bound mono- and di-haem cytochromes c, respectively. The FixQ subunit protects the core complex in the presence of oxygen from proteolytic degradation [PMID: 11864982]. This entry represents the mono-haem FixO subunit.

Contributing signatures

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