CYB_PHYME
ID CYB_PHYME Reviewed; 383 AA.
AC Q35522;
DT 15-JUL-1999, integrated into UniProtKB/Swiss-Prot.
DT 01-NOV-1996, sequence version 1.
DT 03-AUG-2022, entry version 96.
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=cob; Synonyms=cytB;
OS Phytophthora megasperma (Potato pink rot fungus).
OG Mitochondrion.
OC Eukaryota; Sar; Stramenopiles; Oomycota; Peronosporales; Peronosporaceae;
OC Phytophthora.
OX NCBI_TaxID=4788;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC STRAIN=695T;
RA Clary S.A., Hudspeth M.E.S.;
RT "Oomycete mtDNA: nucleotide sequence of the cob region from Phytophthora
RT megasperma.";
RL Submitted (OCT-1993) to the EMBL/GenBank/DDBJ databases.
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: Fungal cytochrome b-c1 complex contains 10 subunits; 3
CC respiratory subunits, 2 core proteins and 5 low-molecular weight
CC proteins. Cytochrome b-c1 complex is a homodimer.
CC {ECO:0000250|UniProtKB:P00163}.
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 only eight transmembrane helices, not
CC nine as predicted by bioinformatics tools.
CC {ECO:0000250|UniProtKB:P00163}.
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DR EMBL; L16863; AAA32026.2; -; Genomic_DNA.
DR AlphaFoldDB; Q35522; -.
DR SMR; Q35522; -.
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 3: Inferred from homology;
KW Electron transport; Heme; Iron; Membrane; Metal-binding; Mitochondrion;
KW Mitochondrion inner membrane; Respiratory chain; Transmembrane;
KW Transmembrane helix; Transport; Ubiquinone.
FT CHAIN 1..383
FT /note="Cytochrome b"
FT /id="PRO_0000061751"
FT TRANSMEM 31..51
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TRANSMEM 75..97
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TRANSMEM 112..132
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TRANSMEM 178..198
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TRANSMEM 224..244
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TRANSMEM 288..308
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TRANSMEM 320..340
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TRANSMEM 347..367
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT BINDING 81
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:0000255|PROSITE-ProRule:PRU00968"
FT BINDING 95
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:0000255|PROSITE-ProRule:PRU00968"
FT BINDING 182
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:0000255|PROSITE-ProRule:PRU00968"
FT BINDING 196
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:0000255|PROSITE-ProRule:PRU00968"
FT BINDING 201
FT /ligand="a ubiquinone"
FT /ligand_id="ChEBI:CHEBI:16389"
FT /evidence="ECO:0000250|UniProtKB:P00157"
SQ SEQUENCE 383 AA; 44268 MW; 100741AB4EEFFD0B CRC64;
MRWNKKSLFA VLNNHLIDYP TPINLNYFFG FGSLAGIMLV VQILTGIFLA MHYTPHIDLA
FNSVEHIMRD VNNGWLMRYT HANGASFFFI VVYVHIFRGL YYGSYITPRE ALWCSGVIIF
ILMMATAFMG YVLPWGQMSF WGATVITNLF SAIPLIGKDI VDWLWGGFAV DNPTLNRFFS
LHFTFPFVIV GAVLIHLILL HEVGSNNPLG ITLKTENIPF YPYFYTKDLF GLMVLFLVFF
IFIFYYPNTL GHPDNYIEAN PMKTPLHIVP EWYFLPFYAI LRSIPNKIGG VIAMFGSLIV
LLTIPFTNSS EIRSTAFRPI FKVCYWLLVV AFLLLGWVGQ CPVEYPYTEI GIISMIYYFF
FFIIIIPFLG KFETYLVRYN TNK
