Cytochrome c oxidase or complex IV (CIV) is the terminal enzyme of our respiratory chains. It is a large membrane protein (200kDa) composed of 14 subunits. Three are encoded by the mitochondrial DNA and form the catalytic core but the function of the eleven other subunits, which are nuclear DNA encoded and unique to mitochondrial forms of the enzyme, remain unknown. Of particular interest are evidences for roles in supercomplex formation and allosteric regulation of CIV core catalytic activity. We will address these key questions using a combination of biochemical, biophysical and structural techniques on mitochondrial enzymes from different sources.
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