Cytochrome C oxidase (COX) is the terminal enzyme of the
mitochondrial respiratory chain. It is a multi-subunit enzyme
complex that couples the transfer of electrons from cytochrome c to
molecular oxygen and contributes to a proton electrochemical
gradient across the inner mitochondrial membrane. The complex
consists of 13 mitochondrial- and nuclear-encoded subunits. The
mitochondrially-encoded subunits perform the electron transfer and
proton pumping activities. The functions of the nuclear-encoded
subunits are unknown but they may play a role in the regulation and
assembly of the complex. This gene encodes the nuclear-encoded
subunit Vb of the human mitochondrial respiratory chain enzyme.
