COX1
Function
Component of the cytochrome c oxidase, the last enzyme in the mitochondrial electron transport chain which drives oxidative phosphorylation. The respiratory chain contains 3 multisubunit complexes succinate dehydrogenase (complex II, CII), ubiquinol-cytochrome c oxidoreductase (cytochrome b-c1 complex, complex III, CIII) and cytochrome c oxidase (complex IV, CIV), that cooperate to transfer electrons derived from NADH and succinate to molecular oxygen, creating an electrochemical gradient over the inner membrane that drives transmembrane transport and the ATP synthase. Cytochrome c oxidase is the component of the respiratory chain that catalyzes the reduction of oxygen to water. Electrons originating from reduced cytochrome c in the intermembrane space (IMS) are transferred via the dinuclear copper A center (CU(A)) of COX2 and heme A of COX1 to the active site in COX1, a binuclear center (BNC) formed by heme A3 and copper B (CU(B)). The BNC reduces molecular oxygen to 2 water molecules using 4 electrons from cytochrome c in the IMS and 4 protons from the mitochondrial matrix (Probable). COX1 is a catalytic core subunit containing heme A and the active site BNC with heme A3 and the copper atom CU(B) (PubMed:30598554).
Pathway
Energy metabolism; oxidative phosphorylation.
Post-translational modifications
The N-terminus is blocked.
Sequence Similarities
Belongs to the heme-copper respiratory oxidase family.
Cellular localization
- Mitochondrion inner membrane
- Multi-pass membrane protein
Alternative names
OXI3, Q0045, COX1, Cytochrome c oxidase subunit 1, Cytochrome c oxidase polypeptide I