Translocases;
Catalysing the translocation of protons;
Linked to oxidoreductase reactions
BRITE hierarchy

ferrocytochrome-c:oxygen oxidoreductase

4 ferrocytochrome c + O2 + 8 H+[side 1] = 4 ferricytochrome c + 2 H2O + 4 H+[side 2] [RN:R00081]

R00081;
(other) R00082
Reaction

ferrocytochrome c [CPD:C00126];
O2 [CPD:C00007];
H+[side 1]

An oligomeric membrane heme-Cu:O2 reductase-type enzyme that terminates the respiratory chains of aerobic and facultative aerobic organisms. The reduction of O2 to water is accompanied by the extrusion of four protons. The cytochrome-aa3 enzymes of mitochondria and many bacterial species are the most abundant group, but other variations, such as the bacterial cytochrome-cbb3 enzymes, also exist. All of the variants have a conserved catalytic core subunit (subunit I) that contains a low-spin heme (of a- or b-type), a binuclear metal centre composed of a high-spin heme iron (of a-, o-, or b-type heme, referred to as a3, o3 or b3 heme), and a Cu atom (CuB). Besides subunit I, the enzyme usually has at least two other core subunits: subunit II is the primary electron acceptor; subunit III usually does not contain any cofactors, but in the case of cbb3-type enzymes it is a diheme c-type cytochrome. While most bacterial enzymes consist of only 3--4 subunits, the mitochondrial enzyme is much more complex and contains 14 subunits.

EC 7.1.1.9 created 1961 as EC 1.9.3.1, modified 2000, transferred 2019 to EC 7.1.1.9, modified 2021