COX3_ARBLI
ID COX3_ARBLI Reviewed; 109 AA.
AC Q33752;
DT 15-JUL-1998, integrated into UniProtKB/Swiss-Prot.
DT 01-NOV-1996, sequence version 1.
DT 25-MAY-2022, entry version 89.
DE RecName: Full=Cytochrome c oxidase subunit 3;
DE EC=7.1.1.9;
DE AltName: Full=Cytochrome c oxidase polypeptide III;
DE Flags: Fragment;
GN Name=COIII;
OS Arbacia lixula (Black urchin) (Echinus lixula).
OG Mitochondrion.
OC Eukaryota; Metazoa; Echinodermata; Eleutherozoa; Echinozoa; Echinoidea;
OC Euechinoidea; Echinacea; Arbacioida; Arbaciidae; Arbacia.
OX NCBI_TaxID=7640;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX PubMed=1681410; DOI=10.1093/oxfordjournals.molbev.a040661;
RA de Giorgi C., Lanave C., Musci M.D., Saccone C.;
RT "Mitochondrial DNA in the sea urchin Arbacia lixula: evolutionary
RT inferences from nucleotide sequence analysis.";
RL Mol. Biol. Evol. 8:515-529(1991).
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; M74839; AAA98044.1; -; Genomic_DNA.
DR AlphaFoldDB; Q33752; -.
DR SMR; Q33752; -.
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..109
FT /note="Cytochrome c oxidase subunit 3"
FT /id="PRO_0000183738"
FT TRANSMEM 7..27
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TRANSMEM 45..65
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TRANSMEM 87..107
FT /note="Helical"
FT /evidence="ECO:0000255"
FT NON_TER 1
SQ SEQUENCE 109 AA; 12511 MW; 3B4617A8F7512963 CRC64;
AGNRTEAVQA LFLTVALGIY FTILQAWEYY DSPFTIADSV YGSTFFVATG FHGLHVINST
TFLLVCLFRL INFHFSAHHH FGFEAAAWYW DFVDVVVAFS LYMHIWWGS
