Cytochrome c oxidase subunit 5B, mitochondrial (Cytochrome c oxidase polypeptide Vb)
1_MASRL 6_ LRGAG 11_ TLAAQ 16_ ALRAR 21_ GPSGA 26_ AAMRS 31_ MASGG 36_ GVPTD 41_ EEQAT 46_ GLERE 51_ IMLAA 56_ KKGLD 61_ PYNVL 66_ APKGA 71_ SGTRE 76_ DPNLV 81_ PSISN 86_ KRIVG 91_ CICEE 96_ DNTSV 101_ VWFWL 106_ HKGEA 111_ QRCPR 116_ CGAHY 121_KLVPQ
1: Component of the cytochrome c oxidase, the last enzyme in the mitochondrial electron transport chain which drives oxidative phosphorylation. The respiratory chain contains 3 multisubunit complexes succinate dehydrogenase (complex II, CII), ubiquinol-cytochrome c oxidoreductase (cytochrome b-c1 complex, complex III, CIII) and cytochrome c oxidase (complex IV, CIV), that cooperate to transfer electrons derived from NADH and succinate to molecular oxygen, creating an electrochemical gradient over the inner membrane that drives transmembrane transport and the ATP synthase. Cytochrome c oxidase is the component of the respiratory chain that catalyzes the reduction of oxygen to water. Electrons originating from reduced cytochrome c in the intermembrane space (IMS) are transferred via the dinuclear copper A center (CU(A)) of subunit 2 and heme A of subunit 1 to the active site in subunit 1, a binuclear center (BNC) formed by heme A3 and copper B (CU(B)). The BNC reduces molecular oxygen to 2 water molecules using 4 electrons from cytochrome c in the IMS and 4 protons from the mitochondrial matrix