ID COX3_BRALA Reviewed; 262 AA. AC P69215; O47425; DT 15-FEB-2005, integrated into UniProtKB/Swiss-Prot. DT 15-FEB-2005, sequence version 1. DT 22-FEB-2023, entry version 75. DE RecName: Full=Cytochrome c oxidase subunit 3; DE EC=7.1.1.9; DE AltName: Full=Cytochrome c oxidase polypeptide III; GN Name=COIII; OS Branchiostoma lanceolatum (Common lancelet) (Amphioxus lanceolatum). OG Mitochondrion. OC Eukaryota; Metazoa; Chordata; Cephalochordata; Leptocardii; Amphioxiformes; OC Branchiostomatidae; Branchiostoma. OX NCBI_TaxID=7740; RN [1] RP NUCLEOTIDE SEQUENCE [GENOMIC DNA]. RX PubMed=9628930; DOI=10.1093/nar/26.13.3279; RA Spruyt N., Delarbre C., Gachelin G., Laudet V.; RT "Complete sequence of the amphioxus (Branchiostoma lanceolatum) RT mitochondrial genome: relations to vertebrates."; RL Nucleic Acids Res. 26:3279-3285(1998). 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 a catalytic core of 3 subunits and CC several supernumerary subunits. The complex exists as a monomer or a CC dimer and forms supercomplexes (SCs) in the inner mitochondrial CC membrane with ubiquinol-cytochrome c oxidoreductase (cytochrome b-c1 CC complex, complex III, CIII). {ECO:0000250|UniProtKB:P00420}. CC -!- SUBCELLULAR LOCATION: Mitochondrion inner membrane CC {ECO:0000250|UniProtKB:P00420}; Multi-pass membrane protein CC {ECO:0000250|UniProtKB:P00420}. 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; Y16474; CAA76253.1; -; Genomic_DNA. DR PIR; H71390; H71390. DR RefSeq; NP_007543.1; NC_001912.1. DR AlphaFoldDB; P69215; -. DR SMR; P69215; -. DR GeneID; 808215; -. DR CTD; 4514; -. DR GO; GO:0005743; C:mitochondrial inner membrane; IEA:UniProtKB-SubCell. 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..262 FT /note="Cytochrome c oxidase subunit 3" FT /id="PRO_0000183748" FT TRANSMEM 11..31 FT /note="Helical" FT /evidence="ECO:0000255" FT TRANSMEM 32..52 FT /note="Helical" FT /evidence="ECO:0000255" FT TRANSMEM 83..103 FT /note="Helical" FT /evidence="ECO:0000255" FT TRANSMEM 125..147 FT /note="Helical" FT /evidence="ECO:0000255" FT TRANSMEM 160..180 FT /note="Helical" FT /evidence="ECO:0000255" FT TRANSMEM 198..218 FT /note="Helical" FT /evidence="ECO:0000255" FT TRANSMEM 240..260 FT /note="Helical" FT /evidence="ECO:0000255" SQ SEQUENCE 262 AA; 29711 MW; 6D93D8338AC870D8 CRC64; MTGYQPHPWH LVEPSPWPLV GGSAAFTLTV GLVMWFHYNS ISLMILGLVM IVATMIQWWR DVIREATFQG CHTSYVLSGL RRGMVLFIVS EVFFFLAFFW AFFHSSLAPT VELGVTWPPV GVHPLNAFAV PLLNTAVLLS SGVTVTWAHH ALMEGKRTEA IQSLAITVML GLYFTGLQAW EYYEAPFTIA DSVYGSTFFV ATGFHGLHVI IGSTFLMVCL GRQVFYHYTS SHHFGFEAAA WYWHFVDVVW LFLYVCIYWW GS //