COX42_THUOB
ID COX42_THUOB Reviewed; 176 AA.
AC P80971; Q9I8T9;
DT 01-NOV-1997, integrated into UniProtKB/Swiss-Prot.
DT 03-APR-2002, sequence version 2.
DT 03-AUG-2022, entry version 90.
DE RecName: Full=Cytochrome c oxidase subunit 4 isoform 2, mitochondrial;
DE AltName: Full=Cytochrome c oxidase subunit IV isoform 2;
DE Short=COX IV-2;
DE Flags: Precursor;
OS Thunnus obesus (Bigeye tuna).
OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC Actinopterygii; Neopterygii; Teleostei; Neoteleostei; Acanthomorphata;
OC Pelagiaria; Scombriformes; Scombridae; Thunnus.
OX NCBI_TaxID=8241;
RN [1]
RP NUCLEOTIDE SEQUENCE [MRNA].
RC TISSUE=Heart, Liver, and Muscle;
RX PubMed=11004496; DOI=10.1016/s0167-4781(00)00083-x;
RA Huettemann M.;
RT "New isoforms of cytochrome c oxidase subunit IV in tuna fish.";
RL Biochim. Biophys. Acta 1492:242-246(2000).
RN [2]
RP PROTEIN SEQUENCE OF 29-38.
RC TISSUE=Heart, and Liver;
RX PubMed=9310366; DOI=10.1111/j.1432-1033.1997.t01-1-00099.x;
RA Arnold S., Lee I., Kim M., Song E., Linder D., Lottspeich F., Kadenbach B.;
RT "The subunit structure of cytochrome-c oxidase from tuna heart and liver.";
RL Eur. J. Biochem. 248:99-103(1997).
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:P00424}.
CC -!- PATHWAY: Energy metabolism; oxidative phosphorylation.
CC {ECO:0000250|UniProtKB:P00424}.
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:P00423}.
CC -!- SUBCELLULAR LOCATION: Mitochondrion inner membrane
CC {ECO:0000250|UniProtKB:P00423}; Single-pass membrane protein
CC {ECO:0000250|UniProtKB:P00423}.
CC -!- SIMILARITY: Belongs to the cytochrome c oxidase IV family.
CC {ECO:0000305}.
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DR EMBL; AF204871; AAF79934.1; -; mRNA.
DR PIR; S77980; S77980.
DR AlphaFoldDB; P80971; -.
DR SMR; P80971; -.
DR UniPathway; UPA00705; -.
DR GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
DR GO; GO:0005751; C:mitochondrial respiratory chain complex IV; IEA:InterPro.
DR GO; GO:0006123; P:mitochondrial electron transport, cytochrome c to oxygen; IEA:InterPro.
DR CDD; cd00922; Cyt_c_Oxidase_IV; 1.
DR Gene3D; 1.10.442.10; -; 1.
DR InterPro; IPR013288; Cyt_c_oxidase_su4.
DR InterPro; IPR004203; Cyt_c_oxidase_su4_fam.
DR InterPro; IPR036639; Cyt_c_oxidase_su4_sf.
DR PANTHER; PTHR10707; PTHR10707; 1.
DR Pfam; PF02936; COX4; 1.
DR PRINTS; PR01873; CYTCOXIDASE4.
DR SUPFAM; SSF81406; SSF81406; 1.
PE 1: Evidence at protein level;
KW Direct protein sequencing; Membrane; Mitochondrion;
KW Mitochondrion inner membrane; Transit peptide; Transmembrane;
KW Transmembrane helix.
FT TRANSIT 1..28
FT /note="Mitochondrion"
FT /evidence="ECO:0000269|PubMed:9310366"
FT CHAIN 29..176
FT /note="Cytochrome c oxidase subunit 4 isoform 2,
FT mitochondrial"
FT /id="PRO_0000006093"
FT TOPO_DOM 29..106
FT /note="Mitochondrial matrix"
FT /evidence="ECO:0000250|UniProtKB:P00423"
FT TRANSMEM 107..132
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00423"
FT TOPO_DOM 133..176
FT /note="Mitochondrial intermembrane"
FT /evidence="ECO:0000250|UniProtKB:P00423"
FT CONFLICT 33
FT /note="L -> H (in Ref. 2; AA sequence)"
FT /evidence="ECO:0000305"
SQ SEQUENCE 176 AA; 20470 MW; 4EEB4EF17BC58AD4 CRC64;
MLRLTAGRVR SLLAGRATAA FSTSSARMAS HDLEVAESVD MSKPLYWDRL DTPLPDRPYK
EDLTAADKSL KQKEKGPWGQ LSKEEKIALY RLMFCQTYSE MKQPSSEWKT VFGGIFIFLG
FTGLVVWWQA LYVYPPRPRT FDDEWKAKQL KRMLDMRVNP IEGFSAKWDY EKGQWK
