The cytochrome c oxidase (COX) are the terminal enzymes in the respiratory chain. Cytochrome c oxidase catalyzes the transfer of reducing equivalents from cytochrome c to molecular oxygen and pumps protons across the inner mitochondrial membrane.
Mitochondrial DNA encodes 3 COX subunits, I-III (MIM.516030), and nuclear DNA encodes 10 (MIM.123870).
Members
3 mitochondrial COX genes (COX1, COX2, COX3), one mitochondrial tRNA(ser) (MTTS1) (MIM.590080)
| mitochondrial COX genes | COX1 | COX2 | COX3 | COX4 | ||
| nuclear COX genes | COX5 | COX6 | COX7 | COX8 | COX9 | COX10 |
| nuclear COX genes | COX11 | COX12 | COX13 | COX14 | COX15 |
Pathology
Deficiencies in the activity of cytochrome c oxidases, COXs deficiency, mitochondrial respiratory chain complex IV deficiency (MIM.220110)
COX10 (mutations in progressive mitochondrial encephalopathy with proximal renal tubulopathy due to cytochrome C oxidase deficiency) (MIM.602125)
COX15 (mutations in early-onset fatal hypertrophic cardiomyopathy)
SCO1 (17p12-12) (mutations in early-onset hepatic failure with neurologic disorder) (MIM.603644)
SCO2 (22q13) (fatal infantile cardioencephalomyopathy due to cytochrome C oxydase deficiency (MIM.604272)
frequent cause of autosomal recessive mitochondrial disease in infants.
COX15 mutations in fatal infantile hypertrophic cardiomyopathy
SCO2 mutations in fatal infantile cardioencephalomyopathy (MIM.604377)
References
Barrientos A, Barros MH, Valnot I, Rotig A, Rustin P, Tzagoloff A. Cytochrome oxidase in health and disease. Gene. 2002 Mar 6;286(1):53-63. PMID: 11943460
Shoubridge EA. Nuclear genetic defects of oxidative phosphorylation. Hum Mol Genet. 2001 Oct 1;10(20):2277-84. PMID: 11673411
Smeitink J, van den Heuvel L, DiMauro S. The genetics and pathology of oxidative phosphorylation. Nat Rev Genet. 2001 May;2(5):342-52. PMID: 11331900