CYB_CYSCR
ID CYB_CYSCR Reviewed; 379 AA.
AC Q34070; Q08H59; Q34065; Q34069;
DT 15-JUL-1999, integrated into UniProtKB/Swiss-Prot.
DT 01-NOV-1996, sequence version 1.
DT 03-AUG-2022, entry version 102.
DE RecName: Full=Cytochrome b;
DE AltName: Full=Complex III subunit 3;
DE AltName: Full=Complex III subunit III;
DE AltName: Full=Cytochrome b-c1 complex subunit 3;
DE AltName: Full=Ubiquinol-cytochrome-c reductase complex cytochrome b subunit;
GN Name=MT-CYB; Synonyms=COB, CYTB, MTCYB;
OS Cystophora cristata (Hooded seal) (Phoca cristata).
OG Mitochondrion.
OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia;
OC Eutheria; Laurasiatheria; Carnivora; Caniformia; Phocidae; Cystophora.
OX NCBI_TaxID=39293;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX PubMed=7714914; DOI=10.1007/bf00166598;
RA Arnason U., Bodin K., Gullberg A., Ledje C., Mouchaty S.;
RT "A molecular view of pinniped relationships with particular emphasis on the
RT true seals.";
RL J. Mol. Evol. 40:78-85(1995).
RN [2]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX PubMed=16815048; DOI=10.1016/j.ympev.2006.05.022;
RA Arnason U., Gullberg A., Janke A., Kullberg M., Lehman N., Petrov E.A.,
RA Vainola R.;
RT "Pinniped phylogeny and a new hypothesis for their origin and dispersal.";
RL Mol. Phylogenet. Evol. 41:345-354(2006).
RN [3]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 1-134.
RA Carr S.M., Perry E.A.;
RT "Intra- and interfamilial systematic relationships of phocid seals as
RT indicated by mitochondrial DNA sequences.";
RL (In) Dizon A.E., Chivers S.J., Perrin W.F. (eds.);
RL Molecular genetics of marine mammals, pp.277-290, Society for marine
RL mammalogy, Kansas (1997).
RN [4]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 51-130.
RC TISSUE=Muscle;
RA Perry E.A., Carr S.M., Bartlett S.E., Davidson W.S.;
RT "A phylogenetic perspective on the evolution of reproductive behavior in
RT pagophilic seals of the Northwest Atlantic as indicated by mitochondrial
RT DNA sequences.";
RL J. Mammal. 76:22-31(1995).
CC -!- FUNCTION: Component of the ubiquinol-cytochrome c reductase complex
CC (complex III or cytochrome b-c1 complex) that is part of the
CC mitochondrial respiratory chain. The b-c1 complex mediates electron
CC transfer from ubiquinol to cytochrome c. Contributes to the generation
CC of a proton gradient across the mitochondrial membrane that is then
CC used for ATP synthesis. {ECO:0000250|UniProtKB:P00157}.
CC -!- COFACTOR:
CC Name=heme b; Xref=ChEBI:CHEBI:60344;
CC Evidence={ECO:0000250|UniProtKB:P00157};
CC Note=Binds 2 heme b groups non-covalently.
CC {ECO:0000250|UniProtKB:P00157};
CC -!- SUBUNIT: The cytochrome bc1 complex contains 11 subunits: 3 respiratory
CC subunits (MT-CYB, CYC1 and UQCRFS1), 2 core proteins (UQCRC1 and
CC UQCRC2) and 6 low-molecular weight proteins (UQCRH/QCR6, UQCRB/QCR7,
CC UQCRQ/QCR8, UQCR10/QCR9, UQCR11/QCR10 and a cleavage product of
CC UQCRFS1). This cytochrome bc1 complex then forms a dimer.
CC {ECO:0000250|UniProtKB:P00157}.
CC -!- SUBCELLULAR LOCATION: Mitochondrion inner membrane
CC {ECO:0000250|UniProtKB:P00157}; Multi-pass membrane protein
CC {ECO:0000250|UniProtKB:P00157}.
CC -!- MISCELLANEOUS: Heme 1 (or BL or b562) is low-potential and absorbs at
CC about 562 nm, and heme 2 (or BH or b566) is high-potential and absorbs
CC at about 566 nm. {ECO:0000250}.
CC -!- SIMILARITY: Belongs to the cytochrome b family. {ECO:0000255|PROSITE-
CC ProRule:PRU00967, ECO:0000255|PROSITE-ProRule:PRU00968}.
CC -!- CAUTION: The full-length protein contains only eight transmembrane
CC helices, not nine as predicted by bioinformatics tools.
CC {ECO:0000250|UniProtKB:P00157}.
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DR EMBL; X82294; CAA57737.1; -; Genomic_DNA.
DR EMBL; AM181028; CAJ57039.1; -; Genomic_DNA.
DR EMBL; L19124; AAA74098.1; -; Genomic_DNA.
DR EMBL; L39209; AAC28750.1; -; Genomic_DNA.
DR PIR; S58460; S58460.
DR RefSeq; YP_778850.1; NC_008427.1.
DR AlphaFoldDB; Q34070; -.
DR SMR; Q34070; -.
DR GeneID; 4356322; -.
DR CTD; 4519; -.
DR GO; GO:0005743; C:mitochondrial inner membrane; IEA:UniProtKB-SubCell.
DR GO; GO:0045275; C:respiratory chain complex III; IEA:InterPro.
DR GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR GO; GO:0008121; F:ubiquinol-cytochrome-c reductase activity; IEA:InterPro.
DR GO; GO:0022904; P:respiratory electron transport chain; IEA:InterPro.
DR CDD; cd00290; cytochrome_b_C; 1.
DR CDD; cd00284; Cytochrome_b_N; 1.
DR Gene3D; 1.20.810.10; -; 1.
DR InterPro; IPR005798; Cyt_b/b6_C.
DR InterPro; IPR036150; Cyt_b/b6_C_sf.
DR InterPro; IPR005797; Cyt_b/b6_N.
DR InterPro; IPR027387; Cytb/b6-like_sf.
DR InterPro; IPR030689; Cytochrome_b.
DR InterPro; IPR016174; Di-haem_cyt_TM.
DR Pfam; PF00032; Cytochrom_B_C; 1.
DR Pfam; PF00033; Cytochrome_B; 1.
DR PIRSF; PIRSF038885; COB; 1.
DR SUPFAM; SSF81342; SSF81342; 1.
DR SUPFAM; SSF81648; SSF81648; 1.
DR PROSITE; PS51003; CYTB_CTER; 1.
DR PROSITE; PS51002; CYTB_NTER; 1.
PE 3: Inferred from homology;
KW Electron transport; Heme; Iron; Membrane; Metal-binding; Mitochondrion;
KW Mitochondrion inner membrane; Respiratory chain; Transmembrane;
KW Transmembrane helix; Transport; Ubiquinone.
FT CHAIN 1..379
FT /note="Cytochrome b"
FT /id="PRO_0000060854"
FT TRANSMEM 33..53
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00157"
FT TRANSMEM 77..98
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00157"
FT TRANSMEM 113..133
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00157"
FT TRANSMEM 178..198
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00157"
FT TRANSMEM 226..246
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00157"
FT TRANSMEM 288..308
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00157"
FT TRANSMEM 320..340
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00157"
FT TRANSMEM 347..367
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00157"
FT BINDING 83
FT /ligand="heme b"
FT /ligand_id="ChEBI:CHEBI:60344"
FT /ligand_label="b562"
FT /ligand_part="Fe"
FT /ligand_part_id="ChEBI:CHEBI:18248"
FT /note="axial binding residue"
FT /evidence="ECO:0000250|UniProtKB:P00157"
FT BINDING 97
FT /ligand="heme b"
FT /ligand_id="ChEBI:CHEBI:60344"
FT /ligand_label="b566"
FT /ligand_part="Fe"
FT /ligand_part_id="ChEBI:CHEBI:18248"
FT /note="axial binding residue"
FT /evidence="ECO:0000250|UniProtKB:P00157"
FT BINDING 182
FT /ligand="heme b"
FT /ligand_id="ChEBI:CHEBI:60344"
FT /ligand_label="b562"
FT /ligand_part="Fe"
FT /ligand_part_id="ChEBI:CHEBI:18248"
FT /note="axial binding residue"
FT /evidence="ECO:0000250|UniProtKB:P00157"
FT BINDING 196
FT /ligand="heme b"
FT /ligand_id="ChEBI:CHEBI:60344"
FT /ligand_label="b566"
FT /ligand_part="Fe"
FT /ligand_part_id="ChEBI:CHEBI:18248"
FT /note="axial binding residue"
FT /evidence="ECO:0000250|UniProtKB:P00157"
FT BINDING 201
FT /ligand="a ubiquinone"
FT /ligand_id="ChEBI:CHEBI:16389"
FT /evidence="ECO:0000250|UniProtKB:P00157"
FT CONFLICT 130
FT /note="G -> S (in Ref. 3; AAA74098)"
FT /evidence="ECO:0000305"
SQ SEQUENCE 379 AA; 42606 MW; 6CAC4C6044EED898 CRC64;
MTNIRKTHPL MKIINNSFID LPTPSNISAW WNFGSLLGIC LILQILTGLF LAMHYTSDTT
TAFSSVTHIC RDVNYGWIIR YLHANGASMF FICLYMHVGR GLYYGSYTFT ETWNIGIILL
FTVMATAFMG YVLPWGQMSF WGATVITNLL SAIPYIGADL VEWIWGGFSV DKATLTRFFA
FHFILPFVVS ALATVHLLFL HETGSNNPSG ITSDSDKIPF HPYYTIKDIL GALLLILVLT
LLVLFSPDLL GDPDNYTPAN PLSTPPHIKP EWYFLFAYAI LRSIPNKLGG VLALVLSILI
LAIMPLLHTS KQRGMMFRPI SQCLFWLLVA DLLTLTWIGG QPVEHPYITI GQLASILYFM
ILLVLMPIAS IIENNILKW
