ID COX3_ANAPL Reviewed; 86 AA. AC P50657; DT 01-OCT-1996, integrated into UniProtKB/Swiss-Prot. DT 01-OCT-1996, sequence version 1. DT 22-FEB-2023, entry version 96. DE RecName: Full=Cytochrome c oxidase subunit 3; DE EC=7.1.1.9; DE AltName: Full=Cytochrome c oxidase polypeptide III; DE Flags: Fragment; GN Name=MT-CO3; Synonyms=COIII, COXIII, MTCO3; OS Anas platyrhynchos (Mallard) (Anas boschas). OG Mitochondrion. OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; OC Archelosauria; Archosauria; Dinosauria; Saurischia; Theropoda; OC Coelurosauria; Aves; Neognathae; Galloanserae; Anseriformes; Anatidae; OC Anatinae; Anas. OX NCBI_TaxID=8839; RN [1] RP NUCLEOTIDE SEQUENCE [GENOMIC DNA]. RC STRAIN=Pekin breed; TISSUE=Liver; RX PubMed=8230253; DOI=10.1007/bf00175506; RA Ramirez V., Savoie P., Morais R.; RT "Molecular characterization and evolution of a duck mitochondrial genome."; RL J. Mol. Evol. 37:296-310(1993). RN [2] RP NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 53-85. RC STRAIN=Pekin breed; TISSUE=Liver; RX PubMed=2390786; DOI=10.1007/bf00313080; RA Desjardins P., Ramirez V., Morais R.; RT "Gene organization of the Peking duck mitochondrial genome."; RL Curr. Genet. 17:515-518(1990). CC -!- FUNCTION: Component of the cytochrome c oxidase, the last enzyme in the CC mitochondrial electron transport chain which drives oxidative CC phosphorylation. The respiratory chain contains 3 multisubunit CC complexes succinate dehydrogenase (complex II, CII), ubiquinol- CC cytochrome c oxidoreductase (cytochrome b-c1 complex, complex III, CC CIII) and cytochrome c oxidase (complex IV, CIV), that cooperate to CC transfer electrons derived from NADH and succinate to molecular oxygen, CC creating an electrochemical gradient over the inner membrane that CC drives transmembrane transport and the ATP synthase. Cytochrome c CC oxidase is the component of the respiratory chain that catalyzes the CC reduction of oxygen to water. Electrons originating from reduced CC cytochrome c in the intermembrane space (IMS) are transferred via the CC dinuclear copper A center (CU(A)) of subunit 2 and heme A of subunit 1 CC to the active site in subunit 1, a binuclear center (BNC) formed by CC heme A3 and copper B (CU(B)). The BNC reduces molecular oxygen to 2 CC water molecules using 4 electrons from cytochrome c in the IMS and 4 CC protons from the mitochondrial matrix. {ECO:0000250|UniProtKB:P00420}. CC -!- CATALYTIC ACTIVITY: CC Reaction=4 Fe(II)-[cytochrome c] + 8 H(+)(in) + O2 = 4 Fe(III)- CC [cytochrome c] + 4 H(+)(out) + 2 H2O; Xref=Rhea:RHEA:11436, CC Rhea:RHEA-COMP:10350, Rhea:RHEA-COMP:14399, ChEBI:CHEBI:15377, CC ChEBI:CHEBI:15378, ChEBI:CHEBI:15379, ChEBI:CHEBI:29033, CC ChEBI:CHEBI:29034; EC=7.1.1.9; CC Evidence={ECO:0000250|UniProtKB:P00420}; CC PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:11437; CC Evidence={ECO:0000250|UniProtKB:P00420}; CC -!- SUBUNIT: Component of the cytochrome c oxidase (complex IV, CIV), a CC multisubunit enzyme composed of 14 subunits. The complex is composed of CC a catalytic core of 3 subunits MT-CO1, MT-CO2 and MT-CO3, encoded in CC the mitochondrial DNA, and 11 supernumerary subunits COX4I, COX5A, CC COX5B, COX6A, COX6B, COX6C, COX7A, COX7B, COX7C, COX8 and NDUFA4, which CC are encoded in the nuclear genome. The complex exists as a monomer or a CC dimer and forms supercomplexes (SCs) in the inner mitochondrial CC membrane with NADH-ubiquinone oxidoreductase (complex I, CI) and CC ubiquinol-cytochrome c oxidoreductase (cytochrome b-c1 complex, complex CC III, CIII), resulting in different assemblies (supercomplex CC SCI(1)III(2)IV(1) and megacomplex MCI(2)III(2)IV(2)). CC {ECO:0000250|UniProtKB:P00415}. CC -!- SUBCELLULAR LOCATION: Mitochondrion inner membrane CC {ECO:0000250|UniProtKB:P00415}; Multi-pass membrane protein CC {ECO:0000250|UniProtKB:P00415}. CC -!- SIMILARITY: Belongs to the cytochrome c oxidase subunit 3 family. CC {ECO:0000305}. CC --------------------------------------------------------------------------- CC Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms CC Distributed under the Creative Commons Attribution (CC BY 4.0) License CC --------------------------------------------------------------------------- DR EMBL; L22476; AAA72040.2; -; Genomic_DNA. DR EMBL; X55527; CAA39144.1; -; Genomic_DNA. DR AlphaFoldDB; P50657; -. DR SMR; P50657; -. DR GO; GO:0005743; C:mitochondrial inner membrane; IEA:UniProtKB-SubCell. DR GO; GO:0045277; C:respiratory chain complex IV; ISS:UniProtKB. DR GO; GO:0004129; F:cytochrome-c oxidase activity; IEA:UniProtKB-EC. DR GO; GO:0019646; P:aerobic electron transport chain; IEA:InterPro. DR Gene3D; 1.10.287.70; -; 1. DR InterPro; IPR024791; Cyt_c/ubiquinol_Oxase_su3. DR InterPro; IPR000298; Cyt_c_oxidase-like_su3. DR InterPro; IPR035973; Cyt_c_oxidase_su3-like_sf. DR PANTHER; PTHR11403:SF7; CYTOCHROME C OXIDASE SUBUNIT 3; 1. DR PANTHER; PTHR11403; CYTOCHROME C OXIDASE SUBUNIT III; 1. DR Pfam; PF00510; COX3; 1. DR SUPFAM; SSF81452; Cytochrome c oxidase subunit III-like; 1. DR PROSITE; PS50253; COX3; 1. PE 3: Inferred from homology; KW Membrane; Mitochondrion; Mitochondrion inner membrane; Translocase; KW Transmembrane; Transmembrane helix. FT CHAIN 1..>86 FT /note="Cytochrome c oxidase subunit 3" FT /id="PRO_0000183731" FT TOPO_DOM 1..15 FT /note="Mitochondrial matrix" FT /evidence="ECO:0000250|UniProtKB:P00415" FT TRANSMEM 16..34 FT /note="Helical; Name=I" FT /evidence="ECO:0000250|UniProtKB:P00415" FT TOPO_DOM 35..40 FT /note="Mitochondrial intermembrane" FT /evidence="ECO:0000250|UniProtKB:P00415" FT TRANSMEM 41..66 FT /note="Helical; Name=II" FT /evidence="ECO:0000250|UniProtKB:P00415" FT TOPO_DOM 67..>86 FT /note="Mitochondrial matrix" FT /evidence="ECO:0000250|UniProtKB:P00415" FT NON_TER 86 SQ SEQUENCE 86 AA; 9768 MW; 254F9B780A044400 CRC64; MAHQAHSYHM VDPSPWPIFG AAAALLTTSG LVMWFHYNSS ILLAAGLLSM LLVMLQWWRE IVRESTFQGH HTPTVQKGLR YGMILF //