CYB_EMEND
ID CYB_EMEND Reviewed; 387 AA.
AC P00161;
DT 21-JUL-1986, integrated into UniProtKB/Swiss-Prot.
DT 21-JUL-1986, sequence version 1.
DT 03-AUG-2022, entry version 114.
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=cobA, cytB;
OS Emericella nidulans (Aspergillus nidulans).
OG Mitochondrion.
OC Eukaryota; Fungi; Dikarya; Ascomycota; Pezizomycotina; Eurotiomycetes;
OC Eurotiomycetidae; Eurotiales; Aspergillaceae; Aspergillus;
OC Aspergillus subgen. Nidulantes.
OX NCBI_TaxID=162425;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC STRAIN=yA2 pyroA4 cnxC3;
RX PubMed=7034966; DOI=10.1016/0092-8674(81)90354-8;
RA Waring R.B., Davies R.W., Lee S., Grisi E., Berks M.M., Scazzocchio C.;
RT "The mosaic organization of the apocytochrome b gene of Aspergillus
RT nidulans revealed by DNA sequencing.";
RL Cell 27:4-11(1981).
RN [2]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 142-286.
RC STRAIN=IFM 41094, IFM 41395, IFM 46999, IFM 47004, and IFM 47006;
RX PubMed=9776828; DOI=10.1080/02681219880000231;
RA Wang L., Yokoyama K., Miyaji M., Nishimura K.;
RT "The identification and phylogenetic relationship of pathogenic species of
RT Aspergillus based on the mitochondrial cytochrome b gene.";
RL Med. Mycol. 36:153-164(1998).
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; J01388; AAA31737.1; -; Genomic_DNA.
DR EMBL; J01389; -; NOT_ANNOTATED_CDS; Genomic_DNA.
DR EMBL; AB000580; BAA34147.1; -; Genomic_DNA.
DR EMBL; AB000581; BAA34148.1; -; Genomic_DNA.
DR EMBL; AB000582; BAA34149.1; -; Genomic_DNA.
DR EMBL; AB000598; BAA34163.2; -; Genomic_DNA.
DR EMBL; AB000599; BAA34164.2; -; Genomic_DNA.
DR PIR; A00157; CBASN.
DR AlphaFoldDB; P00161; -.
DR SMR; P00161; -.
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..387
FT /note="Cytochrome b"
FT /id="PRO_0000061743"
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 226..246
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TRANSMEM 290..310
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TRANSMEM 322..342
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TRANSMEM 349..369
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 387 AA; 43522 MW; 087E024264CD79C4 CRC64;
MRILKSHPLL KIVNSYIIDS PQPANLSYLW NFGSLLALCL GIQIVTGVTL AMHYTPSVSE
AFNSVEHIMR DVNNGWLVRY LHSNTASAFF FLVYLHIGRG LYYGSYKTPR TLTWAIGTVI
LIVMMATAFL GYVLPYGQMS LWGATVITNL MSAIPWIGQD IVEFIWGGFS VNNATLNRFF
ALHFLLPFVL AALALMHLIA MHDTVGSGNP LGISANYDRL PFAPYFIFKD LITIFIFFIV
LSIFVFFMPN ALGDSENYVM ANPMQTPPAI VPEWYLLPFY AILRSIPNKL LGVIAMFAAI
LALMVMPITD LSKLRGVQFR PLSKVVFYIF VANFLILMQI GAKHVETPFI EFGQISTIIY
FAYFFVIVPV VSLIENTLVE LGTKKNF
