Cytochrome c oxidase subunit I

Cytochrome c oxidase subunit I (COI or COX1) is a protein that in humans is encoded by the MT-CO1 gene. It is a subunit of the enzyme cytochrome c oxidase (complex IV), which is the last enzyme in the mitochondrial electron transport chain of mitochondria.

Function

COX1 is one of the three mitochondrial DNA (mtDNA)-encoded subunits of cytochrome c oxidase. Cytochrome c oxidase is the terminal enzyme of the mitochondrial respiratory chain that catalyzes the reduction of oxygen to water. Subunits 1-3 form the functional core of the enzyme complex. COX1, the largest subunit, forms the mitochondrial proton channel, and its polypeptide folds into a transmembrane helix that forms the core of the proton pump.

Clinical significance

Mutations in the MT-CO1 gene are associated with a variety of human diseases, including Leber's hereditary optic neuropathy, mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS), and myoclonic epilepsy with ragged-red fibers (MERRF).

See also

• Cytochrome c oxidase
• Mitochondrial DNA
• Mitochondrial disease

External links

• NCBI Gene
• UniProt