ID COX3_ONCMY Reviewed; 261 AA. AC P48172; DT 01-FEB-1996, integrated into UniProtKB/Swiss-Prot. DT 01-FEB-1996, sequence version 1. DT 22-FEB-2023, entry version 111. DE RecName: Full=Cytochrome c oxidase subunit 3; DE EC=7.1.1.9; DE AltName: Full=Cytochrome c oxidase polypeptide III; GN Name=mt-co3; Synonyms=coiii, coxiii, mtco3; OS Oncorhynchus mykiss (Rainbow trout) (Salmo gairdneri). OG Mitochondrion. OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; OC Actinopterygii; Neopterygii; Teleostei; Protacanthopterygii; Salmoniformes; OC Salmonidae; Salmoninae; Oncorhynchus. OX NCBI_TaxID=8022; RN [1] RP NUCLEOTIDE SEQUENCE [GENOMIC DNA]. RC TISSUE=Liver; RX PubMed=8587139; DOI=10.1007/bf00173174; RA Zardoya R., Garrido-Pertierra A., Bautista J.M.; RT "The complete nucleotide sequence of the mitochondrial DNA genome of the RT rainbow trout, Oncorhynchus mykiss."; RL J. Mol. Evol. 41:942-951(1995). RN [2] RP PARTIAL NUCLEOTIDE SEQUENCE. RX PubMed=2550657; DOI=10.1007/bf02100207; RA Thomas W.K., Beckenbach A.T.; RT "Variation in salmonid mitochondrial DNA: evolutionary constraints and RT mechanisms of substitution."; RL J. Mol. Evol. 29:233-245(1989). 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; L29771; AAB03353.1; -; Genomic_DNA. DR PIR; G34012; G34012. DR RefSeq; NP_008296.1; NC_001717.1. DR AlphaFoldDB; P48172; -. DR SMR; P48172; -. DR GeneID; 807973; -. DR KEGG; omy:807973; -. DR CTD; 4514; -. DR OrthoDB; 984876at2759; -. 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 CDD; cd01665; Cyt_c_Oxidase_III; 1. DR Gene3D; 1.10.287.70; -; 1. DR Gene3D; 1.20.120.80; Cytochrome c oxidase, subunit III, four-helix bundle; 1. DR InterPro; IPR024791; Cyt_c/ubiquinol_Oxase_su3. DR InterPro; IPR033945; Cyt_c_oxase_su3_dom. DR InterPro; IPR000298; Cyt_c_oxidase-like_su3. DR InterPro; IPR035973; Cyt_c_oxidase_su3-like_sf. DR InterPro; IPR013833; Cyt_c_oxidase_su3_a-hlx. 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..261 FT /note="Cytochrome c oxidase subunit 3" FT /id="PRO_0000183818" 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..72 FT /note="Mitochondrial matrix" FT /evidence="ECO:0000250|UniProtKB:P00415" FT TRANSMEM 73..105 FT /note="Helical; Name=III" FT /evidence="ECO:0000250|UniProtKB:P00415" FT TOPO_DOM 106..128 FT /note="Mitochondrial intermembrane" FT /evidence="ECO:0000250|UniProtKB:P00415" FT TRANSMEM 129..152 FT /note="Helical; Name=IV" FT /evidence="ECO:0000250|UniProtKB:P00415" FT TOPO_DOM 153..155 FT /note="Mitochondrial matrix" FT /evidence="ECO:0000250|UniProtKB:P00415" FT TRANSMEM 156..183 FT /note="Helical; Name=V" FT /evidence="ECO:0000250|UniProtKB:P00415" FT TOPO_DOM 184..190 FT /note="Mitochondrial intermembrane" FT /evidence="ECO:0000250|UniProtKB:P00415" FT TRANSMEM 191..223 FT /note="Helical; Name=VI" FT /evidence="ECO:0000250|UniProtKB:P00415" FT TOPO_DOM 224..232 FT /note="Mitochondrial matrix" FT /evidence="ECO:0000250|UniProtKB:P00415" FT TRANSMEM 233..256 FT /note="Helical; Name=VII" FT /evidence="ECO:0000250|UniProtKB:P00415" FT TOPO_DOM 257..261 FT /note="Mitochondrial intermembrane" FT /evidence="ECO:0000250|UniProtKB:P00415" SQ SEQUENCE 261 AA; 29675 MW; AD4F7AA21255D96E CRC64; MAHQAHAYHM VDPSPWPLTG AIAALLLTSG TAVWFHFHSL TLLTLGNILL LLTMYQWWRD IIREGTFQGH HTPPVQKGLR YGMILFITSE VFFFLGFFWA FYHASLAPTP ELGGCWPPAG ITTLDPFEVP LLNTAVLLAS GVTVTWAHHS IMEGERKQTI QALTLTILLG FYFTFLQGME YYEAPFTIAD GVYGSTFFVA TGFHGLHVII GSTFLAVCLL RQVQYHFTSE HHFGFEAAAW YWHFVDVVWL FLYVSIYWWG S //