CYB_HIPAM
ID CYB_HIPAM Reviewed; 379 AA.
AC Q33500; O03362; Q9T575;
DT 01-NOV-1997, integrated into UniProtKB/Swiss-Prot.
DT 02-MAY-2002, sequence version 2.
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 Hippopotamus amphibius (Hippopotamus).
OG Mitochondrion.
OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia;
OC Eutheria; Laurasiatheria; Artiodactyla; Whippomorpha; Ancodonta;
OC Hippopotamidae; Hippopotamus.
OX NCBI_TaxID=9833;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RA Irwin D.M., Arnason U.;
RT "Cytochrome b gene of marine mammals: phylogeny and evolution.";
RL J. Mammal. Evol. 2:37-55(1994).
RN [2]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC STRAIN=Isolate T-1464 extr. 4907;
RX PubMed=9159933; DOI=10.1093/oxfordjournals.molbev.a025792;
RA Montgelard C., Catzeflis F.M., Douzery E.J.P.;
RT "Phylogenetic relationships of artiodactyls and cetaceans as deduced from
RT the comparison of cytochrome b and 12S rRNA mitochondrial sequences.";
RL Mol. Biol. Evol. 14:550-559(1997).
RN [3]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX PubMed=9881471; DOI=10.1098/rspb.1998.0567;
RA Ursing B.M., Arnason U.;
RT "Analyses of mitochondrial genomes strongly support a hippopotamus-whale
RT clade.";
RL Proc. R. Soc. B 265:2251-2255(1998).
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; U07565; AAA19918.1; -; Genomic_DNA.
DR EMBL; Y08813; CAA70047.1; -; Genomic_DNA.
DR EMBL; AJ010957; CAA09440.1; -; Genomic_DNA.
DR RefSeq; NP_008802.1; NC_000889.1.
DR AlphaFoldDB; Q33500; -.
DR SMR; Q33500; -.
DR GeneID; 808671; -.
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_0000061040"
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 107
FT /note="Y -> H (in Ref. 3; CAA09440)"
FT /evidence="ECO:0000305"
FT CONFLICT 188
FT /note="V -> I (in Ref. 1; AAA19918)"
FT /evidence="ECO:0000305"
FT CONFLICT 207
FT /note="N -> K (in Ref. 1; AAA19918)"
FT /evidence="ECO:0000305"
FT CONFLICT 246
FT /note="A -> T (in Ref. 1; AAA19918)"
FT /evidence="ECO:0000305"
FT CONFLICT 353
FT /note="V -> L (in Ref. 1; AAA19918)"
FT /evidence="ECO:0000305"
SQ SEQUENCE 379 AA; 42452 MW; E3CEC157EC18332F CRC64;
MTNIRKSHPL MKIINDAFVD LPAPSNISSW WNFGSLLGVC LILQILTGLF LAMHYTPDTL
TAFSSVTHIC RDVNYGWVIR YMHANGASIF FICLFTHVGR GLYYGSYTFL ETWNIGVILL
LTTMATAFMG YVLPWGQMSF WGATVITNLL SAIPYIGTDL VEWIWGGFSV DKATLTRFFA
FHFILPFVIT ALAIVHLLFL HETGSNNPTG IPSNADKIPF HPYYTIKDIL GILLLMTTLL
TLTLFAPDLL GDPDNYTPAN PLSTPPHIKP EWYFLFAYAI LRSIPNKLGG VLALALSILI
LALIPMLHTS KQRSLMFRPL SQCLFWALIA DLLTLTWIGG QPVEHPFIII GQVASILYFL
LILVLMPVAG IIENKLLKW
