CYB_XENLA
ID CYB_XENLA Reviewed; 380 AA.
AC P00160;
DT 21-JUL-1986, integrated into UniProtKB/Swiss-Prot.
DT 01-JAN-1990, sequence version 2.
DT 03-AUG-2022, entry version 123.
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 Xenopus laevis (African clawed frog).
OG Mitochondrion.
OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Amphibia;
OC Batrachia; Anura; Pipoidea; Pipidae; Xenopodinae; Xenopus; Xenopus.
OX NCBI_TaxID=8355;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX PubMed=2415430; DOI=10.1016/0378-1119(85)90070-8;
RA Dunon-Bluteau D., Volovitch M., Brun G.;
RT "Nucleotide sequence of a Xenopus laevis mitochondrial DNA fragment
RT containing the D-loop, flanking tRNA genes and the apocytochrome b gene.";
RL Gene 36:65-78(1985).
RN [2]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX PubMed=4019494; DOI=10.1016/s0021-9258(17)39303-1;
RA Roe B.A., Ma D.-P., Wilson R.K., Wong J.F.-H.;
RT "The complete nucleotide sequence of the Xenopus laevis mitochondrial
RT genome.";
RL J. Biol. Chem. 260:9759-9774(1985).
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; M10217; AAA66470.1; -; Genomic_DNA.
DR EMBL; M10188; AAA65520.2; -; Genomic_DNA.
DR PIR; A23955; CBXL.
DR RefSeq; NP_008146.1; NC_001573.1.
DR AlphaFoldDB; P00160; -.
DR SMR; P00160; -.
DR GeneID; 2642080; -.
DR KEGG; xla:2642080; -.
DR CTD; 4519; -.
DR Xenbase; XB-GENE-6462351; cytb.L.
DR OrthoDB; 1125966at2759; -.
DR Proteomes; UP000186698; Mitochondrion MT.
DR Bgee; 2642080; Expressed in brain and 19 other tissues.
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..380
FT /note="Cytochrome b"
FT /id="PRO_0000061726"
FT TRANSMEM 34..54
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00157"
FT TRANSMEM 78..99
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00157"
FT TRANSMEM 114..134
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00157"
FT TRANSMEM 179..199
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00157"
FT TRANSMEM 227..247
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00157"
FT TRANSMEM 289..309
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00157"
FT TRANSMEM 321..341
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00157"
FT TRANSMEM 348..368
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00157"
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:P00157"
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:P00157"
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:P00157"
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:P00157"
FT BINDING 202
FT /ligand="a ubiquinone"
FT /ligand_id="ChEBI:CHEBI:16389"
FT /evidence="ECO:0000250|UniProtKB:P00157"
FT CONFLICT 72
FT /note="R -> F (in Ref. 2; AAA66470)"
FT /evidence="ECO:0000305"
FT CONFLICT 78
FT /note="W -> L (in Ref. 2; AAA66470)"
FT /evidence="ECO:0000305"
FT CONFLICT 88
FT /note="A -> L (in Ref. 2; AAA66470)"
FT /evidence="ECO:0000305"
FT CONFLICT 154
FT /note="I -> K (in Ref. 2; AAA66470)"
FT /evidence="ECO:0000305"
FT CONFLICT 165..166
FT /note="IW -> SL (in Ref. 2; AAA66470)"
FT /evidence="ECO:0000305"
FT CONFLICT 285..286
FT /note="IP -> M (in Ref. 2; AAA66470)"
FT /evidence="ECO:0000305"
SQ SEQUENCE 380 AA; 42715 MW; 62B9C2C020DB1E90 CRC64;
MAPNIRKSHP LIKIINNSFI DLPTPSNISS LWNFGSLLGV CLIAQIITGL FLAMHYTADT
SMAFSSVAHI CRDVNYGWLI RNLHANGASF FFICIYLHIG RGLYYGSFLY KETWNIGVIL
LFLVMATAFV GYVLPWGQMS FWGATVITNL LSAIPYIGNV LVQWIWGGFS VDNATLTRFF
AFHFLLPFII AGASILHLLF LHETGSTNPT GLNSDPDKVP FHPYFSYKDL LGFLIMLTAL
TLLAMFSPNL LGDPDNFTPA NPLITPPHIK PEWYFLFAYA ILRSIPNKLG GVLALVLSIL
ILALMPLLHT SKQRSLMFRP FTQIMFWALV ADTLILTWIG GQPVEDPYTM IGQLASVIYF
SIFIIMFPLM GWVENKLLNW
