CYB_ARATH
ID CYB_ARATH Reviewed; 393 AA.
AC P42792; F4IND9; P93289;
DT 01-NOV-1995, integrated into UniProtKB/Swiss-Prot.
DT 17-JAN-2003, sequence version 2.
DT 03-AUG-2022, entry version 165.
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;
GN OrderedLocusNames=AtMg00220 {ECO:0000312|Araport:ATMG00220};
GN and
GN OrderedLocusNames=At2g07727 {ECO:0000312|Araport:AT2G07727};
OS Arabidopsis thaliana (Mouse-ear cress).
OG Mitochondrion.
OC Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae;
OC rosids; malvids; Brassicales; Brassicaceae; Camelineae; Arabidopsis.
OX NCBI_TaxID=3702;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC STRAIN=cv. Columbia;
RX PubMed=7916674; DOI=10.1007/bf00336785;
RA Brandt P., Unseld M., Eckert-Ossenkopp U., Brennicke A.;
RT "An rps14 pseudogene is transcribed and edited in Arabidopsis
RT mitochondria.";
RL Curr. Genet. 24:330-336(1993).
RN [2]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=cv. C24;
RX PubMed=8988169; DOI=10.1038/ng0197-57;
RA Unseld M., Marienfeld J.R., Brandt P., Brennicke A.;
RT "The mitochondrial genome of Arabidopsis thaliana contains 57 genes in
RT 366,924 nucleotides.";
RL Nat. Genet. 15:57-61(1997).
RN [3]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=cv. C24, cv. Columbia, and cv. Landsberg erecta;
RX PubMed=21951689; DOI=10.1186/1741-7007-9-64;
RA Davila J.I., Arrieta-Montiel M.P., Wamboldt Y., Cao J., Hagmann J.,
RA Shedge V., Xu Y.Z., Weigel D., Mackenzie S.A.;
RT "Double-strand break repair processes drive evolution of the mitochondrial
RT genome in Arabidopsis.";
RL BMC Biol. 9:64-64(2011).
RN [4]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA] (AT2G07727).
RC STRAIN=cv. Columbia;
RX PubMed=10617197; DOI=10.1038/45471;
RA Lin X., Kaul S., Rounsley S.D., Shea T.P., Benito M.-I., Town C.D.,
RA Fujii C.Y., Mason T.M., Bowman C.L., Barnstead M.E., Feldblyum T.V.,
RA Buell C.R., Ketchum K.A., Lee J.J., Ronning C.M., Koo H.L., Moffat K.S.,
RA Cronin L.A., Shen M., Pai G., Van Aken S., Umayam L., Tallon L.J.,
RA Gill J.E., Adams M.D., Carrera A.J., Creasy T.H., Goodman H.M.,
RA Somerville C.R., Copenhaver G.P., Preuss D., Nierman W.C., White O.,
RA Eisen J.A., Salzberg S.L., Fraser C.M., Venter J.C.;
RT "Sequence and analysis of chromosome 2 of the plant Arabidopsis thaliana.";
RL Nature 402:761-768(1999).
RN [5]
RP GENOME REANNOTATION (AT2G07727).
RC STRAIN=cv. Columbia;
RX PubMed=27862469; DOI=10.1111/tpj.13415;
RA Cheng C.Y., Krishnakumar V., Chan A.P., Thibaud-Nissen F., Schobel S.,
RA Town C.D.;
RT "Araport11: a complete reannotation of the Arabidopsis thaliana reference
RT genome.";
RL Plant J. 89:789-804(2017).
RN [6]
RP RNA EDITING.
RX PubMed=10611383; DOI=10.1073/pnas.96.26.15324;
RA Giege P., Brennicke A.;
RT "RNA editing in Arabidopsis mitochondria effects 441 C to U changes in
RT ORFs.";
RL Proc. Natl. Acad. Sci. U.S.A. 96:15324-15329(1999).
RN [7]
RP SUBUNIT.
RX PubMed=12970493; DOI=10.1104/pp.103.024620;
RA Eubel H., Jansch L., Braun H.P.;
RT "New insights into the respiratory chain of plant mitochondria.
RT Supercomplexes and a unique composition of complex II.";
RL Plant Physiol. 133:274-286(2003).
RN [8]
RP SUBCELLULAR LOCATION, SUBUNIT, AND IDENTIFICATION BY MASS SPECTROMETRY.
RX PubMed=18189341; DOI=10.1021/pr700595p;
RA Meyer E.H., Taylor N.L., Millar A.H.;
RT "Resolving and identifying protein components of plant mitochondrial
RT respiratory complexes using three dimensions of gel electrophoresis.";
RL J. Proteome Res. 7:786-794(2008).
RN [9]
RP SUBUNIT, IDENTIFICATION BY MASS SPECTROMETRY, AND NOMENCLATURE.
RC STRAIN=cv. Columbia;
RX PubMed=18305213; DOI=10.1104/pp.107.111260;
RA Zsigmond L., Rigo G., Szarka A., Szekely G., Oetvoes K., Darula Z.,
RA Medzihradszky K.F., Koncz C., Koncz Z., Szabados L.;
RT "Arabidopsis PPR40 connects abiotic stress responses to mitochondrial
RT electron transport.";
RL Plant Physiol. 146:1721-1737(2008).
CC -!- FUNCTION: Component of the ubiquinol-cytochrome c oxidoreductase, a
CC multisubunit transmembrane complex that is part of the mitochondrial
CC electron transport chain which drives oxidative phosphorylation. The
CC respiratory chain contains 3 multisubunit complexes succinate
CC dehydrogenase (complex II, CII), ubiquinol-cytochrome c oxidoreductase
CC (cytochrome b-c1 complex, complex III, CIII) and cytochrome c oxidase
CC (complex IV, CIV), that cooperate to transfer electrons derived from
CC NADH and succinate to molecular oxygen, creating an electrochemical
CC gradient over the inner membrane that drives transmembrane transport
CC and the ATP synthase. The cytochrome b-c1 complex catalyzes electron
CC transfer from ubiquinol to cytochrome c, linking this redox reaction to
CC translocation of protons across the mitochondrial inner membrane, with
CC protons being carried across the membrane as hydrogens on the quinol.
CC In the process called Q cycle, 2 protons are consumed from the matrix,
CC 4 protons are released into the intermembrane space and 2 electrons are
CC passed to cytochrome c. Cytochrome b is a catalytic core subunit
CC containing 2 b-type hemes BL and BH topographically segregated in the
CC quinone reduction (Qi) and quinol oxidation (Q0) sites on opposite
CC sides of the membrane. {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: Component of the ubiquinol-cytochrome c oxidoreductase
CC (cytochrome b-c1 complex, complex III, CIII), a multisubunit enzyme
CC composed of 10 subunits. The complex is composed of 3 respiratory
CC subunits cytochrome b (MT-CYB), cytochrome c1 (CYC1-1 or CYC1-2) and
CC Rieske protein (UCR1-1 or UCR1-2), 2 core protein subunits MPPalpha1
CC (or MPPalpha2) and MPPB, and 5 low-molecular weight protein subunits
CC QCR7-1 (or QCR7-2), UCRQ-1 (or UCRQ-2), QCR9, UCRY and probably QCR6-1
CC (or QCR6-2) (PubMed:18189341, PubMed:18305213). The complex exists as
CC an obligatory dimer and forms supercomplexes (SCs) in the inner
CC mitochondrial membrane with NADH-ubiquinone oxidoreductase (complex I,
CC CI), resulting in different assemblies (supercomplexes SCI(1)III(2) and
CC SCI(2)III(4)) (PubMed:12970493). {ECO:0000269|PubMed:12970493,
CC ECO:0000269|PubMed:18189341, ECO:0000269|PubMed:18305213}.
CC -!- SUBCELLULAR LOCATION: Mitochondrion inner membrane
CC {ECO:0000269|PubMed:18189341}; Multi-pass membrane protein
CC {ECO:0000250|UniProtKB:P00163}.
CC -!- RNA EDITING: Modified_positions=96 {ECO:0000269|PubMed:10611383}, 109
CC {ECO:0000269|PubMed:10611383}, 190 {ECO:0000269|PubMed:10611383}, 285
CC {ECO:0000269|PubMed:10611383}, 303 {ECO:0000269|PubMed:10611383}, 328
CC {ECO:0000269|PubMed:10611383}, 362 {ECO:0000269|PubMed:10611383};
CC -!- MISCELLANEOUS: A stretch of 270 kb of the mitochondrial genome is
CC duplicated within the centromere of chromosome 2 resulting in the
CC duplication of the gene. The expression of this duplicated gene
CC (At2g07727) is not demonstrated. It is also probably not RNA edited and
CC therefore differs in all the positions known to be edited.
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 protein contains only eight transmembrane helices, not
CC nine as predicted by bioinformatics tools.
CC {ECO:0000250|UniProtKB:P00163}.
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DR EMBL; X67736; CAA47966.1; ALT_SEQ; Genomic_DNA.
DR EMBL; Y08501; CAA69766.3; ALT_SEQ; Genomic_DNA.
DR EMBL; JF729200; AEK01250.1; ALT_SEQ; Genomic_DNA.
DR EMBL; JF729201; AEK01285.1; ALT_SEQ; Genomic_DNA.
DR EMBL; JF729202; AEK01318.1; ALT_SEQ; Genomic_DNA.
DR EMBL; AC006225; AAM15165.1; ALT_SEQ; Genomic_DNA.
DR EMBL; CP002685; AEC06108.1; ALT_SEQ; Genomic_DNA.
DR PIR; S38960; S38960.
DR RefSeq; NP_085492.1; NC_001284.2.
DR RefSeq; NP_178804.1; NM_126762.3.
DR AlphaFoldDB; P42792; -.
DR SMR; P42792; -.
DR BioGRID; 789; 1.
DR IntAct; P42792; 12.
DR MINT; P42792; -.
DR STRING; 3702.AT2G07727.1; -.
DR PaxDb; P42792; -.
DR PeptideAtlas; P42792; -.
DR PRIDE; P42792; -.
DR GeneID; 815400; -.
DR KEGG; ath:AT2G07727; -.
DR Araport; AT2G07727; -.
DR Araport; ATMG00220; -.
DR eggNOG; KOG4663; Eukaryota.
DR HOGENOM; CLU_031114_3_0_1; -.
DR InParanoid; P42792; -.
DR OrthoDB; 1125966at2759; -.
DR PhylomeDB; P42792; -.
DR BioCyc; ARA:ATMG00220-MON; -.
DR BioCyc; ARA:MON-8804; -.
DR BioCyc; MetaCyc:ATMG00220-MON; -.
DR PRO; PR:P42792; -.
DR Proteomes; UP000006548; Chromosome 2.
DR Proteomes; UP000006548; Mitochondrion (cv. C24).
DR Genevisible; P42792; AT.
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 1: Evidence at protein level;
KW Electron transport; Heme; Iron; Membrane; Metal-binding; Mitochondrion;
KW Mitochondrion inner membrane; Reference proteome; Respiratory chain;
KW RNA editing; Transmembrane; Transmembrane helix; Transport; Ubiquinone.
FT CHAIN 1..393
FT /note="Cytochrome b"
FT /id="PRO_0000060615"
FT TOPO_DOM 1..33
FT /note="Mitochondrial matrix"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TRANSMEM 34..57
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TOPO_DOM 58..80
FT /note="Mitochondrial intermembrane"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TRANSMEM 81..108
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TOPO_DOM 109..116
FT /note="Mitochondrial matrix"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TRANSMEM 117..141
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TOPO_DOM 142..178
FT /note="Mitochondrial intermembrane"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TRANSMEM 179..210
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TOPO_DOM 211..229
FT /note="Mitochondrial matrix"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TRANSMEM 230..252
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TOPO_DOM 253..293
FT /note="Mitochondrial intermembrane"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TRANSMEM 294..314
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TOPO_DOM 315..325
FT /note="Mitochondrial matrix"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TRANSMEM 326..346
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TOPO_DOM 347..353
FT /note="Mitochondrial intermembrane"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TRANSMEM 354..370
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TOPO_DOM 371..393
FT /note="Mitochondrial matrix"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT BINDING 88
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 102
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 189
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 203
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 208
FT /ligand="a ubiquinone"
FT /ligand_id="ChEBI:CHEBI:16389"
FT /evidence="ECO:0000250|UniProtKB:P00157"
FT CONFLICT 40
FT /note="P -> S (in Ref. 1; CAA47966)"
FT /evidence="ECO:0000305"
SQ SEQUENCE 393 AA; 44291 MW; 90E736254BFDF95C CRC64;
MTIRNQRFSL LKQPISSTLN QHLVDYPTPS NLSYWWGFGP LAGICLVIQI VTGVFLAMHY
TPHVDLAFNS VEHIMRDVEG GWLLRYMHAN GASMFFIVVY LHIFRGLYYA SYSSPREFVW
CLGVVIFLLM IVTAFIGYVL PWGQMSFWGA TVITSLASAI PVVGDTIVTW LWGGFSVDNA
TLNRFFSLHY LLPFILVGAS LLHLAALHQY GSNNPLGVHS EMDKIAFYPY FYVKDLVGWV
AFAIFFSIWI FYAPNVLGHP DNYIPANPMS TPPHIVPEWY FLPIYAILRS IPDKAGGVAA
IALVFICLLA LPFFKSMYVR SSSFRPIYQG MFWLLLADCL LLGWIGCQPV EAPFVTIGQI
SSLVFFLFFA ITPILGRVGR GIPNSYTDET DHT
