CYB_SOLTU
ID CYB_SOLTU Reviewed; 393 AA.
AC P29757;
DT 01-APR-1993, integrated into UniProtKB/Swiss-Prot.
DT 23-JAN-2007, sequence version 4.
DT 03-AUG-2022, entry version 109.
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;
OS Solanum tuberosum (Potato).
OG Mitochondrion.
OC Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae;
OC asterids; lamiids; Solanales; Solanaceae; Solanoideae; Solaneae; Solanum.
OX NCBI_TaxID=4113;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC STRAIN=cv. Bintje;
RX PubMed=1840690; DOI=10.1007/bf00040650;
RA Zanlungo S., Litvak S., Jordana X.;
RT "Isolation and nucleotide sequence of the potato mitochondrial gene for
RT apocytochrome b.";
RL Plant Mol. Biol. 17:527-530(1991).
RN [2]
RP PROTEIN SEQUENCE OF 2-16.
RC TISSUE=Tuber;
RX PubMed=8420797; DOI=10.1016/0014-5793(93)81200-j;
RA Braun H.-P., Schmitz U.K.;
RT "Purification and sequencing of cytochrome b from potato reveals methionine
RT cleavage of a mitochondrially encoded protein.";
RL FEBS Lett. 316:128-132(1993).
RN [3]
RP RNA EDITING.
RX PubMed=7504589; DOI=10.1007/bf00336787;
RA Zanlungo S., Begu D., Quinones V., Araya A., Jordana X.;
RT "RNA editing of apocytochrome b (cob) transcripts in mitochondria from two
RT genera of plants.";
RL Curr. Genet. 24:344-348(1993).
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: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: 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 -!- PTM: First mitochondrial-encoded protein to be shown to have its N-
CC terminal methionine cleaved off.
CC -!- RNA EDITING: Modified_positions=18 {ECO:0000269|PubMed:7504589}, 100
CC {ECO:0000269|PubMed:7504589}, 109 {ECO:0000269|PubMed:7504589}, 120
CC {ECO:0000269|PubMed:7504589}, 190 {ECO:0000269|PubMed:7504589}, 227
CC {ECO:0000269|PubMed:7504589}, 285 {ECO:0000269|PubMed:7504589}, 303
CC {ECO:0000269|PubMed:7504589}, 328 {ECO:0000269|PubMed:7504589}, 362
CC {ECO:0000269|PubMed:7504589};
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; X58437; CAA41343.1; ALT_SEQ; Genomic_DNA.
DR PIR; S17427; CBPOM.
DR AlphaFoldDB; P29757; -.
DR SMR; P29757; -.
DR InParanoid; P29757; -.
DR Proteomes; UP000011115; Unassembled WGS sequence.
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 Direct protein sequencing; Electron transport; Heme; Iron; Membrane;
KW Metal-binding; Mitochondrion; Mitochondrion inner membrane;
KW Reference proteome; Respiratory chain; RNA editing; Transmembrane;
KW Transmembrane helix; Transport; Ubiquinone.
FT INIT_MET 1
FT /note="Removed"
FT /evidence="ECO:0000269|PubMed:8420797"
FT CHAIN 2..393
FT /note="Cytochrome b"
FT /id="PRO_0000061547"
FT TRANSMEM 38..58
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TRANSMEM 82..104
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TRANSMEM 119..139
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TRANSMEM 185..205
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TRANSMEM 231..251
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TRANSMEM 295..315
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TRANSMEM 327..347
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TRANSMEM 354..373
FT /note="Helical"
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"
SQ SEQUENCE 393 AA; 44283 MW; 6B8E8274C8AE165E CRC64;
MTIRNQRLSL LKQPISSILN QHLIDYPTPS NLSYWWGFGS 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 IPDKVGGVAA
IALVFICLLA LPFFKSMYVR SSSFRPIYQG IFWLLLADCL LLGWIGCQPV EAPFVTIGQI
SSLVFFLFFA ITPILGRVGR GIPNSYTDET DHT
