ID   COX3_DICCI              Reviewed;         431 AA.
AC   Q2LCP9;
DT   04-DEC-2007, integrated into UniProtKB/Swiss-Prot.
DT   21-FEB-2006, 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=cox3;
OS   Dictyostelium citrinum (Slime mold).
OG   Mitochondrion.
OC   Eukaryota; Amoebozoa; Evosea; Eumycetozoa; Dictyostelia; Dictyosteliales;
OC   Dictyosteliaceae; Dictyostelium.
OX   NCBI_TaxID=361072;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RX   PubMed=18413355; DOI=10.1093/molbev/msn088;
RA   Heidel A.J., Gloeckner G.;
RT   "Mitochondrial genome evolution in the social amoebae.";
RL   Mol. Biol. Evol. 25:1440-1450(2008).
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}.
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DR   EMBL; DQ336395; ABC60394.1; -; Genomic_DNA.
DR   RefSeq; YP_492643.1; NC_007787.2.
DR   AlphaFoldDB; Q2LCP9; -.
DR   SMR; Q2LCP9; -.
DR   GeneID; 3912631; -.
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; 1.20.120.80; Cytochrome c oxidase, subunit III, four-helix bundle; 2.
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; 2.
DR   SUPFAM; SSF81452; Cytochrome c oxidase subunit III-like; 2.
DR   PROSITE; PS50253; COX3; 1.
PE   3: Inferred from homology;
KW   Membrane; Mitochondrion; Mitochondrion inner membrane; Translocase;
KW   Transmembrane; Transmembrane helix.
FT   CHAIN           1..431
FT                   /note="Cytochrome c oxidase subunit 3"
FT                   /id="PRO_0000312387"
FT   TRANSMEM        70..90
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        96..116
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        132..152
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        176..196
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        321..341
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        356..376
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        408..428
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
SQ   SEQUENCE   431 AA;  49659 MW;  CEAE1DA818BFBA3A CRC64;
     MKRFFENLFS QTERSVLNTG KKVGAGIAAG EWKNTEWGYP IATQEVIFLA KVFQPQHVKR
     HPYHIVRGTI APLAVTLPLA FFVLNYFGVI SSKIGFVIAL SSFIGGLTIW AISIVFDSLY
     DQQHTYEVKR GLVMGMMMFI ISEIMFFFSF FWSYFYISLS PNIAIGCVWP PYGLTVYSYM
     GLPLLNTVLL LLSGAILTDG YTILTEQKAV HENNEKVIAV EEAFTNLMNL YTKKQSINTL
     TFVDERREKF FAKNDQNAEK KEIAISAGVK ELRDLDWDLY FFENPQNMEP NYKAPTDLSV
     IEYALITIFL KKRNKVIKTR LYFTLVCAVV FLFCQGYEYY FAPFSMNDGI YGSLFFLLTG
     FHGFHVLVGS ILIGIITIRF IVGNFDLLNV GTKFQIFKNK STGFACTLFY WHFVDIVWIF
     LYIVIYWWGS R
//