CYB_SPIPN
ID CYB_SPIPN Reviewed; 396 AA.
AC Q950S3;
DT 06-DEC-2005, integrated into UniProtKB/Swiss-Prot.
DT 01-DEC-2001, sequence version 1.
DT 03-AUG-2022, entry version 84.
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 Spizellomyces punctatus.
OG Mitochondrion.
OC Eukaryota; Fungi; Fungi incertae sedis; Chytridiomycota;
OC Chytridiomycota incertae sedis; Chytridiomycetes; Spizellomycetales;
OC Spizellomycetaceae; Spizellomyces.
OX NCBI_TaxID=109760;
RN [1]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RX PubMed=11861890; DOI=10.1093/oxfordjournals.molbev.a004084;
RA Forget L., Ustinova J., Wang Z., Huss V.A.R., Lang B.F.;
RT "Hyaloraphidium curvatum: a linear mitochondrial genome, tRNA editing, and
RT an evolutionary link to lower fungi.";
RL Mol. Biol. Evol. 19:310-319(2002).
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; AF404303; AAK84235.1; -; Genomic_DNA.
DR RefSeq; NP_150306.1; NC_003052.1.
DR AlphaFoldDB; Q950S3; -.
DR SMR; Q950S3; -.
DR GeneID; 809622; -.
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..396
FT /note="Cytochrome b"
FT /id="PRO_0000061764"
FT TRANSMEM 32..52
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TRANSMEM 76..98
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TRANSMEM 113..133
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TRANSMEM 179..199
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TRANSMEM 225..245
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TRANSMEM 289..309
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TRANSMEM 321..341
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TRANSMEM 348..368
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT BINDING 82
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 96
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 183
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 197
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 202
FT /ligand="a ubiquinone"
FT /ligand_id="ChEBI:CHEBI:16389"
FT /evidence="ECO:0000250|UniProtKB:P00157"
SQ SEQUENCE 396 AA; 45288 MW; 12C8F5D3CEEACD3A CRC64;
MKLTKRNPIL VLVNDFVIDS PLPTNLTYFW NFGSLLGVNL VILIISGLTL AMHYTPNTLL
AFSSVEHIMR DVNNGWLLRY IHANGASFFF IWVYLHIGRN LYYGSYRSPR GLLWSIGVVI
FILMMATAFI GYVLPWGQMS FWGATVITNL LSAIPWIGTD FVLFVWGGFS VDNATLNRFF
SLHYLLPFIL AALVVMHLLA LHQDGSNNPE GISSSSDRLR FHPYFTSKDL VGFVWMAILL
SIFVFFAPYY LGHPDNSIPA NPLVTPHSIV PEWYFLPFYA ILRAIPSKLG GVIAMFGALL
ILFPLALIHT NNVRSNRYRP LLNLLFWIFV FNFFVLLWVG AKPIAQPYIL IGQISTIIYF
LYFVILMILG CIMTYIYTKS NCFFIYFFLY FGCSIL