CYB_RAPCU
ID CYB_RAPCU Reviewed; 267 AA.
AC Q8SG72;
DT 07-JUN-2004, integrated into UniProtKB/Swiss-Prot.
DT 01-JUN-2002, sequence version 1.
DT 03-AUG-2022, entry version 80.
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;
DE Flags: Fragment;
GN Name=MT-CYB; Synonyms=COB, CYTB, MTCYB;
OS Raphus cucullatus (Dodo).
OG Mitochondrion.
OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC Archelosauria; Archosauria; Dinosauria; Saurischia; Theropoda;
OC Coelurosauria; Aves; Neognathae; Columbiformes; Raphidae; Raphus.
OX NCBI_TaxID=187135;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX PubMed=11872833; DOI=10.1126/science.295.5560.1683;
RA Shapiro B., Sibthorpe D., Rambaut A., Austin J., Wragg G.M.,
RA Bininda-Emonds O.R., Lee P.L., Cooper A.;
RT "Flight of the dodo.";
RL Science 295:1683-1683(2002).
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}.
CC ---------------------------------------------------------------------------
CC Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms
CC Distributed under the Creative Commons Attribution (CC BY 4.0) License
CC ---------------------------------------------------------------------------
DR EMBL; AF483338; AAM19505.1; -; Genomic_DNA.
DR AlphaFoldDB; Q8SG72; -.
DR SMR; Q8SG72; -.
DR PRIDE; Q8SG72; -.
DR GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
DR GO; GO:0005743; C:mitochondrial inner membrane; IEA:UniProtKB-SubCell.
DR GO; GO:0070469; C:respirasome; IEA:UniProtKB-KW.
DR GO; GO:0009055; F:electron transfer activity; IEA:InterPro.
DR GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
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; IPR016174; Di-haem_cyt_TM.
DR Pfam; PF00032; Cytochrom_B_C; 1.
DR Pfam; PF00033; Cytochrome_B; 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; Extinct organism protein; Heme; Iron; Membrane;
KW Metal-binding; Mitochondrion; Mitochondrion inner membrane;
KW Respiratory chain; Transmembrane; Transmembrane helix; Transport;
KW Ubiquinone.
FT CHAIN <1..>267
FT /note="Cytochrome b"
FT /id="PRO_0000061489"
FT TRANSMEM 4..24
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00157"
FT TRANSMEM 48..69
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00157"
FT TRANSMEM 84..104
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00157"
FT TRANSMEM 149..169
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00157"
FT TRANSMEM 197..217
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00157"
FT TRANSMEM 259..>267
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00157"
FT BINDING 54
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 68
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 153
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 167
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 172
FT /ligand="a ubiquinone"
FT /ligand_id="ChEBI:CHEBI:16389"
FT /evidence="ECO:0000250|UniProtKB:P00157"
FT NON_TER 1
FT NON_TER 267
SQ SEQUENCE 267 AA; 29830 MW; 9AD0522F09C3B7B7 CRC64;
WWNFGSLLGI CLMTQILTGL LLAAHYTADT TLAFSSVAHT CRDVQYGWLI RNLHANGASF
FFICIYLHIG RGLYYGSYLY KETWNTGVIL LLTLMATAFV GYVLPWGQMS FWGATVITNL
FSAIPYIGQT IVEWAWGGFS VDNPTLTRFF TLHFLLPFMI AGLTIIHLTF LHESGSNNPL
GISSNCDKIP FHPYFSLKDI LGFTLMFLPL MTLALFAPNL LGDPENFTPA NPLVTPPHIK
PEWYFLFAYA ILRSIPNKLG GVLALAA
