Protein: Cytochrome c oxidase subunit 3 (EC 7.1.1.9) (Cytochrome c oxidase polypeptide III) (P00420)
Organism: Saccharomyces cerevisiae (strain ATCC 204508 / S288c) (Baker's yeast)
Function: 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 COX2 and heme A of COX1 to the active site in COX1, 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 (Probable). COX3 is a catalytic core subunit.
Subcellular location: Mitochondrion inner membrane {ECO:0000269|PubMed:30598554}; Multi-pass membrane protein {ECO:0000269|PubMed:30598554}.
Sequence: MTHLERSRHQQHPFHMVMPSPWPIVVSFALLSLALSTALTMHGYIGNMNMVYLALFVLLTSSILWFRDIVAEATYLGDHTMAVRKGINLGFLMFVLSEVLIFAGLFWAYFHSAMSPDVTLGACWPPVGIEAVQPTELPLLNTIILLSSGATVTYSHHALIAGNRNKALSGLLITFWLIVIFVTCQYIEYTNAAFTISDGVYGSVFYAGTGLHFLHMVMLAAMLGVNYWRMRNYHLTAGHHVGYETTIIYTHVLDVIWLFLYVVFYWWGV
InterPro domains: - IPR033945: Cytochrome c oxidase subunit III domain (domain) [24-267]
- IPR024791: Cytochrome c oxidase subunit III (family) [10-268]
- IPR000298: Cytochrome c oxidase subunit III-like (domain) [10-269]
- IPR013833: Cytochrome c oxidase, subunit III, 4-helical bundle (homologous_superfamily) [79-269]
- IPR035973: Cytochrome c oxidase subunit III-like superfamily (homologous_superfamily) [9-268]
Interaction partners: - Cytochrome c1, heme protein, mitochondrial
- Cytochrome c oxidase subunit 8, mitochondrial
- Cytochrome b-c1 complex subunit 1, mitochondrial
- Cytochrome c oxidase subunit 13, mitochondrial
- Cytochrome b-c1 complex subunit Rieske, mitochondrial
- Cytochrome c oxidase subunit 7, mitochondrial
- Cytochrome c oxidase subunit 2
- Cytochrome b
- Cytochrome b-c1 complex subunit 8, mitochondrial
- Cytochrome b-c1 complex subunit 2, mitochondrial
Gene Ontology annotations:
Molecular Function (MF): GO:0003674 (molecular function), GO:0003824 (catalytic activity), GO:0005215 (transporter activity), GO:0022857 (transmembrane transporter activity), GO:0016491 (oxidoreductase activity), GO:0009055 (electron transfer activity), GO:0015075 (monoatomic ion transmembrane transporter activity), GO:0015318 (inorganic molecular entity transmembrane transporter activity), GO:0016675 (oxidoreductase activity, acting on a heme group of donors), GO:0022804 (active transmembrane transporter activity), GO:0015399 (primary active transmembrane transporter activity), GO:0022890 (inorganic cation transmembrane transporter activity), GO:0022853 (active monoatomic ion transmembrane transporter activity), GO:0004129 (cytochrome-c oxidase activity), GO:0008324 (monoatomic cation transmembrane transporter activity), GO:0015453 (oxidoreduction-driven active transmembrane transporter activity), GO:0015078 (proton transmembrane transporter activity)
Biological Process (BP): GO:0008150 (biological process), GO:0009987 (cellular process), GO:0051179 (localization), GO:0051234 (establishment of localization), GO:0055085 (transmembrane transport), GO:0098660 (inorganic ion transmembrane transport), GO:0006810 (transport), GO:0034220 (monoatomic ion transmembrane transport), GO:0098655 (monoatomic cation transmembrane transport), GO:0006811 (monoatomic ion transport), GO:0098662 (inorganic cation transmembrane transport), GO:0006812 (monoatomic cation transport), GO:1902600 (proton transmembrane transport)
Cellular Component (CC): GO:0005575 (cellular component), GO:0032991 (protein-containing complex), GO:0110165 (cellular anatomical entity), GO:0005622 (intracellular anatomical structure), GO:0043226 (organelle), GO:0098798 (mitochondrial protein-containing complex), GO:0016020 (membrane), GO:0098796 (membrane protein complex), GO:0031975 (envelope), GO:1902494 (catalytic complex), GO:0005737 (cytoplasm), GO:0031090 (organelle membrane), GO:0031967 (organelle envelope), GO:0016469 (proton-transporting two-sector ATPase complex), GO:0043229 (intracellular organelle), GO:0045263 (proton-transporting ATP synthase complex, coupling factor F(o)), GO:0098800 (inner mitochondrial membrane protein complex), GO:0033177 (proton-transporting two-sector ATPase complex, proton-transporting domain), GO:0005739 (mitochondrion), GO:1904949 (ATPase complex), GO:0043227 (membrane-bounded organelle), GO:0005740 (mitochondrial envelope), GO:0043231 (intracellular membrane-bounded organelle), GO:0005753 (mitochondrial proton-transporting ATP synthase complex), GO:0000276 (mitochondrial proton-transporting ATP synthase complex, coupling factor F(o)), GO:0019866 (organelle inner membrane), GO:0045259 (proton-transporting ATP synthase complex), GO:0031966 (mitochondrial membrane), GO:0005743 (mitochondrial inner membrane)