ID   COX3_SCHCO              Reviewed;         268 AA.
AC   P14058;
DT   01-JAN-1990, integrated into UniProtKB/Swiss-Prot.
DT   01-FEB-1996, sequence version 2.
DT   25-MAY-2022, entry version 100.
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   Schizophyllum commune (Split gill fungus).
OG   Mitochondrion.
OC   Eukaryota; Fungi; Dikarya; Basidiomycota; Agaricomycotina; Agaricomycetes;
OC   Agaricomycetidae; Agaricales; Schizophyllaceae; Schizophyllum.
OX   NCBI_TaxID=5334;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   PubMed=3214878; DOI=10.1007/bf00419999;
RA   Phelps L.G., Burke J.M., Ullrich R.C., Novotny C.P.;
RT   "Nucleotide base sequence of the mitochondrial COIII gene of Schizophyllum
RT   commune.";
RL   Curr. Genet. 14:401-403(1988).
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; M36270; AAA32065.2; -; Genomic_DNA.
DR   PIR; S07557; S07557.
DR   AlphaFoldDB; P14058; -.
DR   SMR; P14058; -.
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: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; -; 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..268
FT                   /note="Cytochrome c oxidase subunit 3"
FT                   /id="PRO_0000183850"
FT   TRANSMEM        19..39
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        49..69
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        85..105
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        124..144
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        165..185
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        202..222
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        245..265
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
SQ   SEQUENCE   268 AA;  29922 MW;  B90B97B8DAE4265A CRC64;
     MTSIKFYQSF SAHLVQHSPW PILVSFSLFN LAIGTVLTMH GYSHSSTTFD LGLAVTVGSI
     LLWTRDIVIE GSFLGDHTKQ VQEGLIIGFI LFIISEVFAF ISVFWAYFHS ALSPAVELGS
     TWPPVGIIPL DTFSLPLFNT IILLSSGAFV TYGHHAIFSG KRLDSIIGLF LTVALALIFS
     YFQAFEYIHA GFSMSDSVFG TVFFASTGLH GIHVMLGTLF LFVSFLRQVN YQTTKEHNIG
     LETSILYWHF VDLVWLFLFL VVYFWGGA