ID COX3_VICFA Reviewed; 265 AA. AC Q03227; DT 01-OCT-1993, integrated into UniProtKB/Swiss-Prot. DT 01-OCT-1993, sequence version 1. DT 22-FEB-2023, entry version 101. DE RecName: Full=Cytochrome c oxidase subunit 3; DE EC=7.1.1.9; DE AltName: Full=Cytochrome c oxidase polypeptide III; GN Name=COX3; Synonyms=COXIII; OS Vicia faba (Broad bean) (Faba vulgaris). OG Mitochondrion. OC Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta; OC Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae; OC rosids; fabids; Fabales; Fabaceae; Papilionoideae; 50 kb inversion clade; OC NPAAA clade; Hologalegina; IRL clade; Fabeae; Vicia. OX NCBI_TaxID=3906; RN [1] RP NUCLEOTIDE SEQUENCE [GENOMIC DNA]. RX PubMed=2155709; DOI=10.1007/bf00313246; RA Macfarlane J.L., Wahleithner J.A., Wolstenholme D.R.; RT "A gene for cytochrome c oxidase subunit III (COXIII) in broad bean RT mitochondrial DNA: structural features and sequence evolution."; RL Curr. Genet. 17:33-40(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 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; X51690; CAA35988.1; -; Genomic_DNA. DR PIR; A48304; A48304. DR AlphaFoldDB; Q03227; -. DR SMR; Q03227; -. 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..265 FT /note="Cytochrome c oxidase subunit 3" FT /id="PRO_0000183870" FT TRANSMEM 16..36 FT /note="Helical" FT /evidence="ECO:0000255" FT TRANSMEM 41..61 FT /note="Helical" FT /evidence="ECO:0000255" FT TRANSMEM 81..101 FT /note="Helical" FT /evidence="ECO:0000255" FT TRANSMEM 137..157 FT /note="Helical" FT /evidence="ECO:0000255" FT TRANSMEM 162..182 FT /note="Helical" FT /evidence="ECO:0000255" FT TRANSMEM 200..220 FT /note="Helical" FT /evidence="ECO:0000255" FT TRANSMEM 245..265 FT /note="Helical" FT /evidence="ECO:0000255" SQ SEQUENCE 265 AA; 29468 MW; B3F0193D8BF0E9DD CRC64; MIESQRHSYH LVDPSPWPIS GSLGALATTV GGVMYMHSFQ GGATLLSLGL IFILYTMFVW WRDVLRESTL EGHHTKVVQL GPRYGSISFI VSEVMFLFAF FRASSHSSLA PTVEIGGIWP PKGIGVLDPR EIPFLNTPIL LSSGAAVTWA HHAILAGKEK RAVYALVATV SLALVFTGFQ GMEYYQAPFT ISDSIYGSTF FLATGFHGFH VIIGTLFLII CGIRQYLGQM TKEHHVGFEA AAWYWHFVDV VRLFPFVSIY WWGGI //