8.A.182. The Mitochondrial Cytochrome c Oxidase Assembly Protein, COX20 (COX20) Family

Cox20 is essential for the assembly of the mitochondrial respiratory chain complex IV (cytochrome c oxidase (Szklarczyk et al. 2013).  It acts as a chaperone in the early steps of cytochrome c oxidase subunit II maturation, stabilizing the newly synthesized protein and presenting it to metallochaperones SCO1/2 which in turn facilitate the incorporation of the mature MT-CO2/COX2 into the assembling holoenzyme (Bourens et al. 2014). Bi-allelic loss of function variants in COX20 gene causes autosomal recessive sensory neuronopathy (Dong et al. 2021).


 

References:

Bourens, M., A. Boulet, S.C. Leary, and A. Barrientos. (2014). Human COX20 cooperates with SCO1 and SCO2 to mature COX2 and promote the assembly of cytochrome c oxidase. Hum Mol Genet 23: 2901-2913.
Dong, H.L., Y. Ma, H. Yu, Q. Wei, J.Q. Li, G.L. Liu, H.F. Li, L. Chen, D.F. Chen, G. Bai, and Z.Y. Wu. (2021). Bi-allelic loss of function variants in COX20 gene cause autosomal recessive sensory neuronopathy. Brain 144: 2457-2470.
Szklarczyk, R., B.F. Wanschers, L.G. Nijtmans, R.J. Rodenburg, J. Zschocke, N. Dikow, M.A. van den Brand, M.G. Hendriks-Franssen, C. Gilissen, J.A. Veltman, M. Nooteboom, W.J. Koopman, P.H. Willems, J.A. Smeitink, M.A. Huynen, and L.P. van den Heuvel. (2013). A mutation in the FAM36A gene, the human ortholog of COX20, impairs cytochrome c oxidase assembly and is associated with ataxia and muscle hypotonia. Hum Mol Genet 22: 656-667.
Examples:

TC#NameOrganismal TypeExample
8.A.182.1.1

COX20 mitochondrial integral membrane chaparone protein of 118 aas and 2 TMSs.  (See family description for details). 

Cox20 of Homo sapiens

 
8.A.182.1.2

COX20-like protein of 178 aas and 2 TMSs.

COX20 of Chaetomium thermophilum

 
8.A.182.1.3

Uncharacterized COX20 homologous protein of 169 aas and 2 TMSs.

COX20 homolog of Trichoderma asperelloides