ID COX3_MYTED Reviewed; 265 AA. AC P41775; DT 01-NOV-1995, integrated into UniProtKB/Swiss-Prot. DT 01-NOV-1995, sequence version 1. DT 02-SEP-2026, entry version 105. 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 Mytilus edulis (Blue mussel). OG Mitochondrion. OC Eukaryota; Metazoa; Spiralia; Lophotrochozoa; Mollusca; Bivalvia; OC Autobranchia; Pteriomorphia; Mytilida; Mytiloidea; Mytilidae; Mytilinae; OC Mytilus. OX NCBI_TaxID=6550; RN [1] RP NUCLEOTIDE SEQUENCE [GENOMIC DNA]. RX PubMed=1386586; DOI=10.1093/genetics/131.2.397; RA Hoffmann R.J., Boore J.L., Brown W.M.; RT "A novel mitochondrial genome organization for the blue mussel, Mytilus RT edulis."; RL Genetics 131:397-412(1992). RN [2] RP NUCLEOTIDE SEQUENCE [GENOMIC DNA]. RX PubMed=15014161; DOI=10.1093/molbev/msh090; RA Boore J.L., Medina M., Rosenberg L.A.; RT "Complete sequences of the highly rearranged molluscan mitochondrial RT genomes of the scaphopod Graptacme eborea and the bivalve Mytilus edulis."; RL Mol. Biol. Evol. 21:1492-1503(2004). 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] + O2 + 8 H(+)(in) = 4 Fe(III)- CC [cytochrome c] + 2 H2O + 4 H(+)(out); 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; AY484747; AAA31906.3; -; Genomic_DNA. DR PIR; S66600; S66600. DR AlphaFoldDB; P41775; -. DR SMR; P41775; -. DR GO; GO:0005743; C:mitochondrial inner membrane; ISS:UniProtKB. DR GO; GO:0004129; F:cytochrome-c oxidase activity; ISS:UniProtKB. 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_0000183810" FT TRANSMEM 16..36 FT /note="Helical" FT /evidence="ECO:0000255" FT TRANSMEM 40..60 FT /note="Helical" FT /evidence="ECO:0000255" FT TRANSMEM 83..103 FT /note="Helical" FT /evidence="ECO:0000255" FT TRANSMEM 159..179 FT /note="Helical" FT /evidence="ECO:0000255" FT TRANSMEM 198..218 FT /note="Helical" FT /evidence="ECO:0000255" FT TRANSMEM 241..261 FT /note="Helical" FT /evidence="ECO:0000255" SQ SEQUENCE 265 AA; 30792 MW; 8427728B6D994DF7 CRC64; MNRNPYSRYY VPGPSPWPFF VAISANGMAV GLILWLHRTP SFLLMGMSLV CMLLSTFSWW RDLIREGDIG FHTRFVIKSF RDCVALFILS EVMFFFTFFW TFFHNALSPS CELGMRWPPP GIRTPNPSST SLFETGLLIS SGLFVTQAHK SMRLKDYDVG PFIGLVVTIV CGTVFFLVQL REYYWNSYTI ADSVYGSVFY LLTGFHGMHV VVGTIWLMVS LVRLWRGEFS SQRHFGFEAC IWYWHFVDVV WVALWCLVYV WFGGW //