COX3_EQUAS
ID COX3_EQUAS Reviewed; 261 AA.
AC P92481;
DT 15-JUL-1998, integrated into UniProtKB/Swiss-Prot.
DT 01-MAY-1997, sequence version 1.
DT 25-MAY-2022, entry version 102.
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 Equus asinus (Donkey) (Equus africanus asinus).
OG Mitochondrion.
OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia;
OC Eutheria; Laurasiatheria; Perissodactyla; Equidae; Equus.
OX NCBI_TaxID=9793;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC TISSUE=Kidney;
RX PubMed=8875857; DOI=10.1007/bf02337515;
RA Xu X., Gullberg A., Arnason U.;
RT "The complete mitochondrial DNA (mtDNA) of the donkey and mtDNA comparisons
RT among four closely related mammalian species-pairs.";
RL J. Mol. Evol. 43:438-446(1996).
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}.
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DR EMBL; X97337; CAA66020.1; -; Genomic_DNA.
DR PIR; T11369; T11369.
DR RefSeq; NP_007387.1; NC_001788.1.
DR AlphaFoldDB; P92481; -.
DR SMR; P92481; -.
DR GeneID; 808054; -.
DR KEGG; eai:808054; -.
DR CTD; 4514; -.
DR OrthoDB; 1304563at2759; -.
DR GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
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 GO; GO:0008535; P:respiratory chain complex IV assembly; ISS:UniProtKB.
DR CDD; cd01665; Cyt_c_Oxidase_III; 1.
DR Gene3D; 1.20.120.80; -; 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; PTHR11403; 1.
DR Pfam; PF00510; COX3; 1.
DR SUPFAM; SSF81452; SSF81452; 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_0000183772"
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; 29761 MW; EB33C3F0EBE40769 CRC64;
MTHQTHAYHM VNPSPWPLTG ALSALLMTSG LAMWFHFNST LLLALGLLTN ILTMYQWWRD
IIRESTFQGH HTSIVQKGLR YGMILFIISE VFFFSGFFWA FYHSSLAPTP ELGGCWPPTG
IHPLNPLEVP LLNTSVLLAS GVSITWAHHS LMEGNRKNML QGLFITISLG VYFTLLQASE
YYEASFTISD GVYGSTFFVA TGFHGLHVII GSTFLIVCFL RQLKFHFTSS HHFGFEAAAW
YWHFVDVVWL FLYVSIYWWG S
