Cytochrome c oxidase, a 13 sub-unit complex (<db_xref db="EC" dbkey="1.9.3.1"/>) is the terminal oxidase in the mitochondrial electron transport chain. Thisfamily is composed of cytochrome c oxidase subunit IV. The <taxon tax_id="44689">Dictyostelium discoideum</taxon> (Slime mould) member of this family is called COX VI. The <taxon tax_id="4932">Saccharomyces cerevisiae</taxon> protein YGX6_YEAST appears to be the yeast COX IV subunit.