COX4I2
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 subunit 2 and heme A of subunit 1 to the active site in subunit 1, 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.
Involvement in disease
Exocrine pancreatic insufficiency dyserythropoietic anemia and calvarial hyperostosis
EPIDACH
Patients present with pancreatic insufficiency, intestinal malabsorption, failure to thrive, and anemia soon after birth.
None
The disease is caused by variants affecting the gene represented in this entry.
Pathway
Energy metabolism; oxidative phosphorylation.
Sequence Similarities
Belongs to the cytochrome c oxidase IV family.
Tissue Specificity
Highly expressed in lung.
Cellular localization
- Mitochondrion inner membrane
- Single-pass membrane protein
Alternative names
COX4L2, COX4I2, Cytochrome c oxidase subunit IV isoform 2, COX IV-2