QCRB_MYCTO
ID QCRB_MYCTO Reviewed; 549 AA.
AC P9WP36; L0TAG7; P63885; Q10388;
DT 16-APR-2014, integrated into UniProtKB/Swiss-Prot.
DT 16-APR-2014, sequence version 1.
DT 03-AUG-2022, entry version 36.
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=MT2252;
OS Mycobacterium tuberculosis (strain CDC 1551 / Oshkosh).
OC Bacteria; Actinobacteria; Corynebacteriales; Mycobacteriaceae;
OC Mycobacterium; Mycobacterium tuberculosis complex.
OX NCBI_TaxID=83331;
RN [1]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=CDC 1551 / Oshkosh;
RX PubMed=12218036; DOI=10.1128/jb.184.19.5479-5490.2002;
RA Fleischmann R.D., Alland D., Eisen J.A., Carpenter L., White O.,
RA Peterson J.D., DeBoy R.T., Dodson R.J., Gwinn M.L., Haft D.H., Hickey E.K.,
RA Kolonay J.F., Nelson W.C., Umayam L.A., Ermolaeva M.D., Salzberg S.L.,
RA Delcher A., Utterback T.R., Weidman J.F., Khouri H.M., Gill J., Mikula A.,
RA Bishai W., Jacobs W.R. Jr., Venter J.C., Fraser C.M.;
RT "Whole-genome comparison of Mycobacterium tuberculosis clinical and
RT laboratory strains.";
RL J. Bacteriol. 184:5479-5490(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; AE000516; AAK46538.1; -; Genomic_DNA.
DR PIR; E70784; E70784.
DR RefSeq; WP_003899212.1; NZ_KK341227.1.
DR AlphaFoldDB; P9WP36; -.
DR SMR; P9WP36; -.
DR EnsemblBacteria; AAK46538; AAK46538; MT2252.
DR GeneID; 45426172; -.
DR KEGG; mtc:MT2252; -.
DR PATRIC; fig|83331.31.peg.2427; -.
DR HOGENOM; CLU_031114_2_0_11; -.
DR Proteomes; UP000001020; 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 Respiratory chain; Translocase; Transmembrane; Transmembrane helix;
KW Transport.
FT CHAIN 1..549
FT /note="Cytochrome bc1 complex cytochrome b subunit"
FT /id="PRO_0000427020"
FT TRANSMEM 45..65
FT /note="Helical"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00968"
FT TRANSMEM 118..138
FT /note="Helical"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00968"
FT TRANSMEM 146..166
FT /note="Helical"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00968"
FT TRANSMEM 189..209
FT /note="Helical"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00968"
FT TRANSMEM 217..237
FT /note="Helical"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00968"
FT TRANSMEM 266..286
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 381..401
FT /note="Helical"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00968"
FT TRANSMEM 418..438
FT /note="Helical"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00968"
FT BINDING 114
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 128
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 216
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 231
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 549 AA; 61014 MW; 0E75E0BCAA46B3A7 CRC64;
MSPKLSPPNI GEVLARQAED IDTRYHPSAA LRRQLNKVFP THWSFLLGEI ALYSFVVLLI
TGVYLTLFFD PSMVDVTYNG VYQPLRGVEM SRAYQSALDI SFEVRGGLFV RQIHHWAALM
FAAAIMVHLA RIFFTGAFRR PRETNWVIGS LLLILAMFEG YFGYSLPDDL LSGLGLRAAL
SSITLGMPVI GTWLHWALFG GDFPGTILIP RLYALHILLL PGIILALIGL HLALVWFQKH
TQFPGPGRTE HNVVGVRVMP VFAFKSGAFF AAIVGVLGLM GGLLQINPIW NLGPYKPSQV
SAGSQPDFYM MWTEGLARIW PPWEFYFWHH TIPAPVWVAV IMGLVFVLLP AYPFLEKRFT
GDYAHHNLLQ RPRDVPVRTA IGAMAIAFYM VLTLAAMNDI IALKFHISLN ATTWIGRIGM
VILPPFVYFI TYRWCIGLQR SDRSVLEHGV ETGIIKRLPH GAYIELHQPL GPVDEHGHPI
PLQYQGAPLP KRMNKLGSAG SPGSGSFLFA DSAAEDAALR EAGHAAEQRA LAALREHQDS
IMGSPDGEH
