CYB_CAEEL
ID CYB_CAEEL Reviewed; 370 AA.
AC P24890;
DT 01-MAR-1992, integrated into UniProtKB/Swiss-Prot.
DT 01-FEB-1996, sequence version 2.
DT 03-AUG-2022, entry version 146.
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=ctb-1 {ECO:0000312|WormBase:MTCE.21};
GN Synonyms=cob {ECO:0000250|UniProtKB:P00163},
GN cytb {ECO:0000312|WormBase:MTCE.21}, Mtcyb {ECO:0000250|UniProtKB:P00156};
GN ORFNames=MTCE.21 {ECO:0000312|WormBase:MTCE.21};
OS Caenorhabditis elegans.
OG Mitochondrion.
OC Eukaryota; Metazoa; Ecdysozoa; Nematoda; Chromadorea; Rhabditida;
OC Rhabditina; Rhabditomorpha; Rhabditoidea; Rhabditidae; Peloderinae;
OC Caenorhabditis.
OX NCBI_TaxID=6239;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA], AND VARIANT VAL-288.
RC STRAIN=AB1, AB2, Bristol N2, CB4852, CB4853, CB4854, CB4855, CB4856,
RC CB4857, CB4858, KR314, PB303, PB306, RW7000, and TR403;
RX PubMed=12644560; DOI=10.1093/molbev/msg044;
RA Denver D.R., Morris K., Thomas W.K.;
RT "Phylogenetics in Caenorhabditis elegans: an analysis of divergence and
RT outcrossing.";
RL Mol. Biol. Evol. 20:393-400(2003).
RN [2]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=Bristol N2;
RX PubMed=1551572; DOI=10.1093/genetics/130.3.471;
RA Okimoto R., Macfarlane J.L., Clary D.O., Wolstenholme D.R.;
RT "The mitochondrial genomes of two nematodes, Caenorhabditis elegans and
RT Ascaris suum.";
RL Genetics 130:471-498(1992).
RN [3]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 1-25.
RX PubMed=2235493; DOI=10.1093/nar/18.20.6113;
RA Okimoto R., Macfarlane J.L., Wolstenholme D.R.;
RT "Evidence for the frequent use of TTG as the translation initiation codon
RT of mitochondrial protein genes in the nematodes, Ascaris suum and
RT Caenorhabditis elegans.";
RL Nucleic Acids Res. 18:6113-6118(1990).
RN [4]
RP FUNCTION, AND MUTAGENESIS OF ALA-170.
RX PubMed=20971856; DOI=10.1074/jbc.m110.159608;
RA Suthammarak W., Morgan P.G., Sedensky M.M.;
RT "Mutations in mitochondrial complex III uniquely affect complex I in
RT Caenorhabditis elegans.";
RL J. Biol. Chem. 285:40724-40731(2010).
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 (PubMed:20971856). The b-c1 complex
CC mediates electron transfer from ubiquinol to cytochrome c (By
CC similarity). Contributes to the generation of a proton gradient across
CC the mitochondrial membrane that is then used for ATP synthesis
CC (PubMed:20971856). {ECO:0000250|UniProtKB:P00163,
CC ECO:0000269|PubMed:20971856}.
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: The main subunits of complex b-c1 are: cytochrome b,
CC cytochrome c1 and the Rieske protein. {ECO:0000250}.
CC -!- SUBCELLULAR LOCATION: Mitochondrion inner membrane
CC {ECO:0000250|UniProtKB:P00163}; Multi-pass membrane protein
CC {ECO:0000250|UniProtKB:P00163}.
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 an even number of transmembrane helices,
CC fewer than predicted by bioinformatics tools.
CC {ECO:0000250|UniProtKB:P00163}.
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DR EMBL; AY171178; AAO16430.1; -; Genomic_DNA.
DR EMBL; AY171179; AAO16432.1; -; Genomic_DNA.
DR EMBL; AY171180; AAO16434.1; -; Genomic_DNA.
DR EMBL; AY171181; AAO16436.1; -; Genomic_DNA.
DR EMBL; AY171190; AAO16454.1; -; Genomic_DNA.
DR EMBL; AY171182; AAO16438.1; -; Genomic_DNA.
DR EMBL; AY171183; AAO16440.1; -; Genomic_DNA.
DR EMBL; AY171184; AAO16442.1; -; Genomic_DNA.
DR EMBL; AY171185; AAO16444.1; -; Genomic_DNA.
DR EMBL; AY171186; AAO16446.1; -; Genomic_DNA.
DR EMBL; AY171187; AAO16448.1; -; Genomic_DNA.
DR EMBL; AY171188; AAO16450.1; -; Genomic_DNA.
DR EMBL; AY171189; AAO16452.1; -; Genomic_DNA.
DR EMBL; AY171191; AAO16456.1; -; Genomic_DNA.
DR EMBL; AY171192; AAO16458.1; -; Genomic_DNA.
DR EMBL; X54252; CAA38156.1; -; Genomic_DNA.
DR PIR; S26031; S26031.
DR RefSeq; NP_006958.1; NC_001328.1.
DR AlphaFoldDB; P24890; -.
DR SMR; P24890; -.
DR STRING; 6239.MTCE.21; -.
DR EPD; P24890; -.
DR PaxDb; P24890; -.
DR EnsemblMetazoa; MTCE.21.1; MTCE.21.1; WBGene00000829.
DR GeneID; 2565702; -.
DR KEGG; cel:CYTB; -.
DR CTD; 4519; -.
DR WormBase; MTCE.21; CE35348; WBGene00000829; ctb-1.
DR eggNOG; KOG4663; Eukaryota.
DR GeneTree; ENSGT00390000017948; -.
DR HOGENOM; CLU_031114_3_0_1; -.
DR InParanoid; P24890; -.
DR OrthoDB; 1125966at2759; -.
DR PhylomeDB; P24890; -.
DR PRO; PR:P24890; -.
DR Proteomes; UP000001940; Mitochondrion.
DR Bgee; WBGene00000829; Expressed in pharyngeal muscle cell (C elegans) and 4 other tissues.
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; 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 1: Evidence at protein level;
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..370
FT /note="Cytochrome b"
FT /id="PRO_0000060703"
FT TRANSMEM 30..50
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TRANSMEM 74..96
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TRANSMEM 109..129
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TRANSMEM 175..195
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TRANSMEM 221..240
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TRANSMEM 284..304
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TRANSMEM 316..336
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TRANSMEM 342..362
FT /note="Helical"
FT /evidence="ECO:0000255"
FT BINDING 80
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 94
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 179
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 193
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 198
FT /ligand="a ubiquinone"
FT /ligand_id="ChEBI:CHEBI:16389"
FT /evidence="ECO:0000250|UniProtKB:P00157"
FT VARIANT 288
FT /note="I -> V (in strain: AB1, AB2, CB4852, CB4853, CB4855,
FT CB4857, CB4858, KR314 and PB306)"
FT /evidence="ECO:0000269|PubMed:12644560"
FT MUTAGEN 170
FT /note="A->V: In qm189; normal complex III assembly, but a
FT decrease in complex activity."
FT /evidence="ECO:0000269|PubMed:20971856"
SQ SEQUENCE 370 AA; 42582 MW; 63E2C2A0D79972D3 CRC64;
MKINNSLLNF VNGMLVTLPS SKTLTLSWNF GSMLGMVLIF QILTGTFLAF YYTPDSLMAF
STVQYIMYEV NFGWVFRIFH FNGASLFFIF LYLHIFKGLF FMSYRLKKVW MSGLTIYLLV
MMEAFMGYVL VWAQMSFWAA VVITSLLSVI PIWGPTIVTW IWSGFGVTGA TLKFFFVLHF
LLPWAILVIV LGHLIFLHST GSTSSLYCHG DYDKVCFSPE YLGKDAYNIV IWLLFIVLSL
IYPFNLGDAE MFIEADPMMS PVHIVPEWYF LFAYAILRAI PNKVLGVIAL LMSIVTFYFF
ALVNNYTSCL TKLNKFLVFM FIISSTILSW LGQCTVEDPF TILSPLFSFI YFGLAYLMLF
IFMSSKLLFK
