cd00926: CHCH_COA6 (This model is not part of the current CDD release)
CHCH domain found in cytochrome c oxidase assembly factor 6 (COA6) and similar proteins
COA6, also called cytochrome c oxidase subunit VIb, is involved in the maturation of the mitochondrial respiratory chain complex IV subunit MT-CO2/COX2. It is thought to regulate the early steps of complex IV assembly. Mitochondrial respiratory chain complex IV or cytochrome c oxidase is the component of the respiratory chain that catalyzes the transfer of electrons from intermembrane space cytochrome c to molecular oxygen in the matrix and therefore contributes to the proton gradient involved in mitochondrial ATP synthesis. COA6 may also be required for efficient formation of respiratory supercomplexes comprised of complexes III and IV. The family also includes Euglena gracilis ATPEG5, a component of the mitochondrial ATP synthase. ATPEG5 is a structurally conserved ortholog of the cytochrome c oxidase subunit VIb family. Members of this family contain a CHCH ([coiled coil 1]-[helix 1]-[coiled coil 2]-[helix 2]) domain with a disulfide-bonded alpha-hairpin conformation. Unlike other CHCH-containing proteins, the CHCH domain of COA6 contains a C-X9-C motif in the first helix, but the second helix is a C-X10-C motif.
Jiyao W et al.(2023). "The conserved domain database in 2023.",