CYB_PHYMC
ID CYB_PHYMC Reviewed; 379 AA.
AC P41290; Q35406; Q9G7T8;
DT 01-FEB-1995, integrated into UniProtKB/Swiss-Prot.
DT 30-APR-2003, sequence version 2.
DT 03-AUG-2022, entry version 107.
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 Physeter macrocephalus (Sperm whale) (Physeter catodon).
OG Mitochondrion.
OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia;
OC Eutheria; Laurasiatheria; Artiodactyla; Whippomorpha; Cetacea; Odontoceti;
OC Physeteridae; Physeter.
OX NCBI_TaxID=9755;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX PubMed=8107866; DOI=10.1038/367726a0;
RA Arnason U., Gullberg A.;
RT "Relationship of baleen whales established by cytochrome b gene sequence
RT comparison.";
RL Nature 367:726-728(1994).
RN [2]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX PubMed=11027333; DOI=10.1073/pnas.97.21.11343;
RA Cassens I., Vicario S., Waddell V.G., Balchowsky H., Van Belle D., Ding W.,
RA Fan C., Mohan L., Simoes-Lopes P.C., Bastida R., Meyer A., Stanhope M.J.,
RA Milinkovitch M.C.;
RT "Independent adaptation to riverine habitats allowed survival of ancient
RT cetacean lineages.";
RL Proc. Natl. Acad. Sci. U.S.A. 97:11343-11347(2000).
RN [3]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 1-134.
RX PubMed=7755710; DOI=10.1093/oxfordjournals.molbev.a040164;
RA Milinkovitch M.C., Meyer A., Powell J.R.;
RT "Phylogeny of all major groups of cetaceans based on DNA sequences from
RT three mitochondrial genes.";
RL Mol. Biol. Evol. 11:939-948(1994).
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; X75589; CAA53265.1; -; Genomic_DNA.
DR EMBL; AF304073; AAG30915.1; -; Genomic_DNA.
DR EMBL; U13142; AAC48452.1; -; Genomic_DNA.
DR PIR; S43270; S43270.
DR RefSeq; NP_062479.1; NC_002503.2.
DR AlphaFoldDB; P41290; -.
DR SMR; P41290; -.
DR GeneID; 809414; -.
DR KEGG; pcad:809414; -.
DR CTD; 4519; -.
DR OrthoDB; 1125966at2759; -.
DR Proteomes; UP000248484; Mitochondrion MT.
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; Reference proteome; Respiratory chain;
KW Transmembrane; Transmembrane helix; Transport; Ubiquinone.
FT CHAIN 1..379
FT /note="Cytochrome b"
FT /id="PRO_0000061395"
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 102
FT /note="L -> W (in Ref. 1; CAA53265)"
FT /evidence="ECO:0000305"
FT CONFLICT 125
FT /note="A -> T (in Ref. 2; AAG30915)"
FT /evidence="ECO:0000305"
SQ SEQUENCE 379 AA; 42988 MW; 0D299090DBB932B0 CRC64;
MTNIRKSHPL MKIINNAFID LPTPSNISSW WNFGSLLGLC LIMQILTGLF LAMHYTPDTT
TAFSSITHIC RDVNYGWTIR YLHANGASMF FICLYTHMGR GLYYGSYIFQ ETWNVGMMLL
ITVMATAFVG YVLPWGQMSF WAATVITNLL SAIPYIGTTL VEWVWGGFSV DKATLTRFFT
LHFILPFITL TLTMVHLLFL HETGSNNPTG IPSNMDKIPF HPYHTIKDTM GALLLILSLL
TLTLFAPDLL GDPDNYTPAN PLNTPTHIKP EWYFLFAYAI LRSVPNKLGG VLALLLSILI
LVFIPMLHTA KQRSMMFRPF SQFLFWTLIM DLLTLTWIGG QPVEHPYVTV GQLASILYFL
LILILMPTAS LIENKLLKW
