MWDYVKLVALGVVAAIAAYAASQARDLPYMVNMVEVALAAVIALIWVLRTMGDPKPSKDEYFDGVIRAGVIATTFWGIVGFLVAVVIAFQLAFPALNLEFGNGMLNFGRLRPLHTSAVIFAFGGNALIASAFYVVQRTSAARLFGGTALGWFVFWGWQLIIVTAATSYLLGGSQGKEYAELNWHLDILVAVVWVAYLIAFLGTIFKRKEPHIYVANWFYLSFIVTIAMLHIVNNLAVPVSIFGTKSVQLMAGVQDAMTQWWYGHNAVGFFLTAGFLGMMYYFVPKQAERPVYSYKLSIVHFWALIFLYIWAGPHHLHYTALPDWASTLGMVMSVILWMPSWGGMINGLMTLSGAWDKLRTDPVIRMMVVSIGFYGMSTFEGPMMSIKAVNSLSHYTDWTIGHVHSGALGWNGMITFGMLYFLTPRLWGRSGLYSLKLVSWHFWLATIGIVLYASAMWVTGIMEGLMWREVDAQGFLVNAFADTVAAKFPMYVVRGVGGVLYLLGGLIMAYNLWATVAKQPKTANLAVAVPAE Cytochrome BB(3) subunit 1 ctaD Cytochrome c oxidase polypeptide I Cytochrome c oxidase subunit 1 COX1_RHOCA 532 ccoN Cytochrome c oxidase is the component of the respiratory chain that catalyzes the reduction of oxygen to water. Subunits 1- 3 form the functional core of the enzyme complex. Co I is the catalytic subunit of the enzyme. Electrons originating in cytochrome c are transferred via the copper A center of subunit 2 and heme a of subunit 1 to the bimetallic center formed by heme a3 and copper B. This cytochrome c oxidase shows proton pump activity across the membrane in addition to the electron transfer.