CYB_XENBC
ID CYB_XENBC Reviewed; 380 AA.
AC A0EYN2;
DT 16-DEC-2008, integrated into UniProtKB/Swiss-Prot.
DT 28-NOV-2006, sequence version 1.
DT 03-AUG-2022, entry version 59.
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:Cyt-b; Synonyms=Cob, cytb;
OS Xenoturbella bocki (Marine worm).
OG Mitochondrion.
OC Eukaryota; Metazoa; Xenacoelomorpha; Xenoturbellida; Xenoturbellidae;
OC Xenoturbella.
OX NCBI_TaxID=242395;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX PubMed=17051155; DOI=10.1038/nature05241;
RA Bourlat S.J., Juliusdottir T., Lowe C.J., Freeman R., Aronowicz J.,
RA Kirschner M., Lander E.S., Thorndyke M., Nakano H., Kohn A.B., Heyland A.,
RA Moroz L.L., Copley R.R., Telford M.J.;
RT "Deuterostome phylogeny reveals monophyletic chordates and the new phylum
RT Xenoturbellida.";
RL Nature 444:85-88(2006).
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:P00163}.
CC -!- COFACTOR:
CC Name=heme b; Xref=ChEBI:CHEBI:60344;
CC Evidence={ECO:0000250|UniProtKB:P00163};
CC Note=Binds 2 heme b groups non-covalently.
CC {ECO:0000250|UniProtKB:P00163};
CC -!- SUBUNIT: The main subunits of complex b-c1 are: cytochrome b,
CC cytochrome c1 and the Rieske protein. {ECO:0000250}.
CC -!- SUBCELLULAR LOCATION: Mitochondrion inner membrane
CC {ECO:0000250|UniProtKB:P00163}; Multi-pass membrane protein
CC {ECO:0000250|UniProtKB:P00163}.
CC -!- SIMILARITY: Belongs to the cytochrome b family. {ECO:0000255|PROSITE-
CC ProRule:PRU00967, ECO:0000255|PROSITE-ProRule:PRU00968}.
CC -!- CAUTION: The protein contains an even number of transmembrane helices,
CC fewer than predicted by bioinformatics tools.
CC {ECO:0000250|UniProtKB:P00163}.
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DR EMBL; DQ832701; ABG54255.1; -; Genomic_DNA.
DR RefSeq; YP_850987.1; NC_008556.1.
DR GeneID; 4466532; -.
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..380
FT /note="Cytochrome b"
FT /id="PRO_0000357467"
FT TRANSMEM 34..54
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TRANSMEM 78..100
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TRANSMEM 113..133
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TRANSMEM 179..199
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TRANSMEM 225..245
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TRANSMEM 289..309
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TRANSMEM 324..344
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TRANSMEM 349..369
FT /note="Helical"
FT /evidence="ECO:0000255"
FT BINDING 84
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:P00163"
FT BINDING 98
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:P00163"
FT BINDING 183
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:P00163"
FT BINDING 197
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:P00163"
FT BINDING 202
FT /ligand="a ubiquinone"
FT /ligand_id="ChEBI:CHEBI:16389"
FT /evidence="ECO:0000250|UniProtKB:P00157"
SQ SEQUENCE 380 AA; 42849 MW; 960BB45D31A9EC16 CRC64;
MKTPIRKTHP VMKIANTALV DLPSPSNIST WWNFGSLLGL FLTMQIITGI ILAMHYTSEV
DMAFDSISHI TRNVNYGWLM RTMHMNGAAF MFICMYAHMG RGMYYSSYML AETWNIGIII
MIATMATAFM GYVLPWGQMS FWGATVITNL VSAIPYIGTD IVYWLWGGFS VGKATLSRFF
AFHFVLPFVL IALSGVHLLF LHQTGSNNPL GLNSNLDKIP FHSFFSWKDL LGFAXMILIF
CTITLTFPLI MGDPENFNPA NPLSTPPHIQ PEWYFLFAYA ILRSIPNKLG GVVALVGSLI
IPATMMLTHK SMLQPMSFRP ISQVIFWLFC ANFIALSWIG AAPVEDPYIT LGQVFSMLYF
LFFLTAPMIN MLEKKLSLKQ
