CYB_AMICA
ID CYB_AMICA Reviewed; 379 AA.
AC P29663; Q8HQK9; Q9T9I3;
DT 01-APR-1993, integrated into UniProtKB/Swiss-Prot.
DT 23-APR-2003, sequence version 2.
DT 03-AUG-2022, entry version 104.
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 Amia calva (Bowfin).
OG Mitochondrion.
OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC Actinopterygii; Neopterygii; Holostei; Amiiformes; Amiidae; Amia.
OX NCBI_TaxID=7924;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RA Kumazawa Y., Yamaguchi M., Nishida M.;
RT "Mitochondrial molecular clocks and the origin of euteleostean
RT biodiversity: familial radiation of perciforms may have predated the
RT Cretaceous/Tertiary boundary.";
RL (In) Kato M. (eds.);
RL The biology of biodiversity, pp.35-52, Springer-Verlag, Tokyo (1999).
RN [2]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX PubMed=12470943; DOI=10.1016/s1055-7903(02)00331-7;
RA Inoue J.G., Miya M., Tsukamoto K., Nishida M.;
RT "Basal actinopterygian relationships: a mitogenomic perspective on the
RT phylogeny of the 'ancient fish.'.";
RL Mol. Phylogenet. Evol. 26:110-120(2003).
RN [3]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 33-134.
RX PubMed=1663569; DOI=10.1093/oxfordjournals.molbev.a040685;
RA Normark B.B., McCune A.R., Harrison R.G.;
RT "Phylogenetic relationships of neopterygian fishes, inferred from
RT mitochondrial DNA sequences.";
RL Mol. Biol. Evol. 8:819-834(1991).
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 3 respiratory subunits
CC (MT-CYB, CYC1 and UQCRFS1), 2 core proteins (UQCRC1 and UQCRC2) and
CC probably 6 low-molecular weight proteins.
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; AB018999; BAA88877.1; -; Genomic_DNA.
DR EMBL; AB042952; BAB40754.1; -; Genomic_DNA.
DR EMBL; M64887; AAB01439.1; -; Genomic_DNA.
DR RefSeq; NP_839823.1; NC_004742.1.
DR AlphaFoldDB; P29663; -.
DR SMR; P29663; -.
DR GeneID; 807219; -.
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_0000060573"
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 243
FT /note="T -> A (in Ref. 2; BAB40754)"
FT /evidence="ECO:0000305"
SQ SEQUENCE 379 AA; 42726 MW; 57DA07ACCC6F7DF5 CRC64;
MATIRKTHPL ISIINGAFID LPAPVNISVW WNFGSLLGLC LITQIVTGLF LAMHFTSDIS
LAFSSVAHIC RDVNYGWFLR NIHANGASLF FICLYLHIAR GLYYGSYLYK ETWNVGVVLF
LLVMMTAFVG YVLPWGQMSF WGATVITNLL SAFPYIGDTL VQWIWGGFSV DNATLTRFFT
FHFLFPFVIA GASMIHLLFL HETGSNNPLG LNSNVDKITF HPYFSYKDLL GFIILLAGLM
FLTLFSPNLL GDPENFTPAN PLVTPPHIKP EWYFLFAYAI LRSIPNKLGG VLALLFSILI
LMIVPITHTS KQRSSTFRPL TQILFWTLVA DMFILTWIGG QPVEHPFIII GQIASIIYFA
LFLVFAPLAG WVENKMLSW
