QCRB_STRCO
ID QCRB_STRCO Reviewed; 545 AA.
AC Q9X806;
DT 30-MAY-2000, integrated into UniProtKB/Swiss-Prot.
DT 01-NOV-1999, sequence version 1.
DT 03-AUG-2022, entry version 133.
DE RecName: Full=Cytochrome bc1 complex cytochrome b subunit;
DE EC=7.1.1.8 {ECO:0000250|UniProtKB:P9WP37};
DE AltName: Full=Cytochrome bc1 reductase complex subunit QcrB;
DE AltName: Full=Ubiquinol--cytochrome c reductase cytochrome b subunit;
GN Name=qcrB; OrderedLocusNames=SCO2148; ORFNames=SC6G10.21c;
OS Streptomyces coelicolor (strain ATCC BAA-471 / A3(2) / M145).
OC Bacteria; Actinobacteria; Streptomycetales; Streptomycetaceae;
OC Streptomyces; Streptomyces albidoflavus group.
OX NCBI_TaxID=100226;
RN [1]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=ATCC BAA-471 / A3(2) / M145;
RX PubMed=12000953; DOI=10.1038/417141a;
RA Bentley S.D., Chater K.F., Cerdeno-Tarraga A.-M., Challis G.L.,
RA Thomson N.R., James K.D., Harris D.E., Quail M.A., Kieser H., Harper D.,
RA Bateman A., Brown S., Chandra G., Chen C.W., Collins M., Cronin A.,
RA Fraser A., Goble A., Hidalgo J., Hornsby T., Howarth S., Huang C.-H.,
RA Kieser T., Larke L., Murphy L.D., Oliver K., O'Neil S., Rabbinowitsch E.,
RA Rajandream M.A., Rutherford K.M., Rutter S., Seeger K., Saunders D.,
RA Sharp S., Squares R., Squares S., Taylor K., Warren T., Wietzorrek A.,
RA Woodward J.R., Barrell B.G., Parkhill J., Hopwood D.A.;
RT "Complete genome sequence of the model actinomycete Streptomyces coelicolor
RT A3(2).";
RL Nature 417:141-147(2002).
CC -!- FUNCTION: Cytochrome b subunit of the cytochrome bc1 complex, an
CC essential component of the respiratory electron transport chain
CC required for ATP synthesis. The bc1 complex catalyzes the oxidation of
CC ubiquinol and the reduction of cytochrome c in the respiratory chain.
CC The bc1 complex operates through a Q-cycle mechanism that couples
CC electron transfer to generation of the proton gradient that drives ATP
CC synthesis. The cytochrome b subunit contains two ubiquinol reactive
CC sites: the oxidation (QP) site and the reduction (QN) site.
CC {ECO:0000250|UniProtKB:P9WP37}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=a quinol + 2 Fe(III)-[cytochrome c](out) = a quinone + 2
CC Fe(II)-[cytochrome c](out) + 2 H(+)(out); Xref=Rhea:RHEA:11484,
CC Rhea:RHEA-COMP:10350, Rhea:RHEA-COMP:14399, ChEBI:CHEBI:15378,
CC ChEBI:CHEBI:24646, ChEBI:CHEBI:29033, ChEBI:CHEBI:29034,
CC ChEBI:CHEBI:132124; EC=7.1.1.8;
CC Evidence={ECO:0000250|UniProtKB:P9WP37};
CC -!- COFACTOR:
CC Name=heme; Xref=ChEBI:CHEBI:30413;
CC Evidence={ECO:0000250|UniProtKB:P00163};
CC Note=Binds 2 heme groups non-covalently per subunit.
CC {ECO:0000250|UniProtKB:P00163};
CC -!- SUBUNIT: The cytochrome bc1 complex is composed of a cytochrome b
CC (QcrB), the Rieske iron-sulfur protein (QcrA) and a diheme cytochrome c
CC (QcrC) subunit. {ECO:0000250|UniProtKB:P9WP37}.
CC -!- SUBCELLULAR LOCATION: Cell membrane {ECO:0000255}; Multi-pass membrane
CC protein {ECO:0000255}.
CC -!- SIMILARITY: Belongs to the cytochrome b family. {ECO:0000255|PROSITE-
CC ProRule:PRU00968}.
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DR EMBL; AL939111; CAB39875.1; -; Genomic_DNA.
DR PIR; T35530; T35530.
DR RefSeq; NP_626404.1; NC_003888.3.
DR RefSeq; WP_011028167.1; NZ_VNID01000001.1.
DR AlphaFoldDB; Q9X806; -.
DR SMR; Q9X806; -.
DR STRING; 100226.SCO2148; -.
DR TCDB; 3.D.3.5.4; the proton-translocating quinol:cytochrome c reductase (qcr) superfamily.
DR GeneID; 1097582; -.
DR KEGG; sco:SCO2148; -.
DR PATRIC; fig|100226.15.peg.2183; -.
DR eggNOG; COG1290; Bacteria.
DR HOGENOM; CLU_031114_2_0_11; -.
DR InParanoid; Q9X806; -.
DR OMA; WNYGPYD; -.
DR PhylomeDB; Q9X806; -.
DR Proteomes; UP000001973; Chromosome.
DR GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
DR GO; GO:0005886; C:plasma membrane; IEA:UniProtKB-SubCell.
DR GO; GO:0070469; C:respirasome; IEA:UniProtKB-KW.
DR GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR GO; GO:0008121; F:ubiquinol-cytochrome-c reductase activity; IEA:UniProtKB-EC.
DR GO; GO:0022904; P:respiratory electron transport chain; IEA:InterPro.
DR Gene3D; 1.20.810.10; -; 1.
DR InterPro; IPR005797; Cyt_b/b6_N.
DR InterPro; IPR027387; Cytb/b6-like_sf.
DR InterPro; IPR016174; Di-haem_cyt_TM.
DR Pfam; PF13631; Cytochrom_B_N_2; 1.
DR SUPFAM; SSF81342; SSF81342; 1.
DR PROSITE; PS51002; CYTB_NTER; 1.
PE 3: Inferred from homology;
KW Cell membrane; Electron transport; Heme; Iron; Membrane; Metal-binding;
KW Reference proteome; Respiratory chain; Translocase; Transmembrane;
KW Transmembrane helix; Transport.
FT CHAIN 1..545
FT /note="Cytochrome bc1 complex cytochrome b subunit"
FT /id="PRO_0000061928"
FT TRANSMEM 54..74
FT /note="Helical"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00968"
FT TRANSMEM 122..142
FT /note="Helical"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00968"
FT TRANSMEM 150..170
FT /note="Helical"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00968"
FT TRANSMEM 182..202
FT /note="Helical"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00968"
FT TRANSMEM 220..240
FT /note="Helical"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00968"
FT TRANSMEM 269..289
FT /note="Helical"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00968"
FT TRANSMEM 335..355
FT /note="Helical"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00968"
FT TRANSMEM 385..405
FT /note="Helical"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00968"
FT TRANSMEM 413..433
FT /note="Helical"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00968"
FT BINDING 118
FT /ligand="heme"
FT /ligand_id="ChEBI:CHEBI:30413"
FT /ligand_label="1"
FT /ligand_part="Fe"
FT /ligand_part_id="ChEBI:CHEBI:18248"
FT /note="axial binding residue"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00968"
FT BINDING 132
FT /ligand="heme"
FT /ligand_id="ChEBI:CHEBI:30413"
FT /ligand_label="2"
FT /ligand_part="Fe"
FT /ligand_part_id="ChEBI:CHEBI:18248"
FT /note="axial binding residue"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00968"
FT BINDING 219
FT /ligand="heme"
FT /ligand_id="ChEBI:CHEBI:30413"
FT /ligand_label="1"
FT /ligand_part="Fe"
FT /ligand_part_id="ChEBI:CHEBI:18248"
FT /note="axial binding residue"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00968"
FT BINDING 234
FT /ligand="heme"
FT /ligand_id="ChEBI:CHEBI:30413"
FT /ligand_label="2"
FT /ligand_part="Fe"
FT /ligand_part_id="ChEBI:CHEBI:18248"
FT /note="axial binding residue"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00968"
SQ SEQUENCE 545 AA; 60886 MW; 313BBB4CA0CDC91F CRC64;
MSTAANEPSR SRGKAPAGER VADWADGRLG IYSLAKANMR KIFPDHWSFM LGEVCLYSFI
IIILTGVYLT LFFHPSMAEV EYHGSYVPLQ GQMMSEAYAS TLDISFDVRG GLLIRQIHHW
AALIFLAGMF VHMMRVFFTG AFRKPREVNW LFGFLLLVLG MFTGFTGYSL PDDLLSGTGI
RFMEGAILSV PIVGTYISFF LFGGEFPGHD FVSRFYSIHI LLLPGIMLGL LVGHLILVFY
HKHTQFAGPG KTNKNVVGMP LLPVYTAKAG GFFFLVFGVI SVVSAIATIN PIWAIGPYRP
DQVSTGAQPD WYMGFSEGLI RVMPGWEINA WGHTLVLGVF VPLLIFPLVL AAIAVYPFIE
SWVTGDKREH HILDRPRNAP TRTAFGVAWL TVYFVLLIGG GNDLWATHFH LSINAITWFV
RIAFFVGPVV AFIATKRICL GLQRRDKDKV LHGRESGIIK RLPHGEFIEV HEPLSQEQLH
TLTAHEQYQP AEIGPTVDEN GVERKVSGTQ KLRAKLSESY YGEESQIPKP TVEEYKEITS
GHGHH
