Cytochrome c oxidase (yeast mitochondrial) (CIV)

Cytochrome c oxidase (complex IV) is the terminal enzyme of the mitochondrial respiratory chain in yeast. It catalyzes the transfer of electrons from cytochrome c to molecular oxygen, reducing it to water, and couples this process with proton translocation across the inner mitochondrial membrane, contributing to the generation of the proton motive force required for ATP synthesis[2][3][5][6]. The enzyme is a large multi-subunit complex comprising mitochondrially and nuclear-encoded proteins, with a conserved catalytic core (subunits Cox1–3 in yeast) and multiple supernumerary subunits[5][3]. In Saccharomyces cerevisiae and other yeast, complex IV participates in the formation of supercomplexes with complex III, facilitating efficient electron transfer and potentially regulating reactive oxygen species production[2][3][7]. It is essential for aerobic respiration and cellular energy metabolism[2][5][6]. Due to evolutionary conservation, yeast complex IV is a model for studying bioenergetics and mitochondrial diseases[5][6].

Other names

Cytochrome c oxidaseComplex IVMitochondrial respiratory chain complex IVCIVCOXCytochrome aa3 oxidase

Inhibition of electron transfer (e.g., cyanide, azide, CO block oxygen reduction by binding to catalytic site); Blockade of oxygen binding (e.g., CO); Induction of oxidative stress by impairing electron flow; Inhibition of ATP production