CYB_MYTED
ID CYB_MYTED Reviewed; 397 AA.
AC Q00228; Q68SR7;
DT 01-NOV-1995, integrated into UniProtKB/Swiss-Prot.
DT 05-JUL-2005, sequence version 2.
DT 03-AUG-2022, entry version 104.
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 Mytilus edulis (Blue mussel).
OG Mitochondrion.
OC Eukaryota; Metazoa; Spiralia; Lophotrochozoa; Mollusca; Bivalvia;
OC Autobranchia; Pteriomorphia; Mytilida; Mytiloidea; Mytilidae; Mytilinae;
OC Mytilus.
OX NCBI_TaxID=6550;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX PubMed=15014161; DOI=10.1093/molbev/msh090;
RA Boore J.L., Medina M., Rosenberg L.A.;
RT "Complete sequences of the highly rearranged molluscan mitochondrial
RT genomes of the scaphopod Graptacme eborea and the bivalve Mytilus edulis.";
RL Mol. Biol. Evol. 21:1492-1503(2004).
RN [2]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 1-202 AND 333-397.
RX PubMed=1386586; DOI=10.1093/genetics/131.2.397;
RA Hoffmann R.J., Boore J.L., Brown W.M.;
RT "A novel mitochondrial genome organization for the blue mussel, Mytilus
RT edulis.";
RL Genetics 131:397-412(1992).
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:P00157}.
CC -!- COFACTOR:
CC Name=heme b; Xref=ChEBI:CHEBI:60344;
CC Evidence={ECO:0000250|UniProtKB:P00157};
CC Note=Binds 2 heme b groups non-covalently.
CC {ECO:0000250|UniProtKB:P00157};
CC -!- SUBUNIT: The main subunits of complex b-c1 are: cytochrome b,
CC cytochrome c1 and the Rieske protein. {ECO:0000250|UniProtKB:P00157}.
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 full-length protein contains only eight transmembrane
CC helices, not nine as predicted by bioinformatics tools.
CC {ECO:0000250|UniProtKB:P00157}.
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DR EMBL; AY484747; AAT98404.1; -; Genomic_DNA.
DR PIR; S28745; S28745.
DR RefSeq; YP_073336.1; NC_006161.1.
DR AlphaFoldDB; Q00228; -.
DR SMR; Q00228; -.
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..397
FT /note="Cytochrome b"
FT /id="PRO_0000061260"
FT TRANSMEM 48..68
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00157"
FT TRANSMEM 92..113
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00157"
FT TRANSMEM 128..148
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00157"
FT TRANSMEM 193..213
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00157"
FT TRANSMEM 241..261
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00157"
FT TRANSMEM 303..323
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00157"
FT TRANSMEM 335..355
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00157"
FT TRANSMEM 362..382
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00157"
FT BINDING 98
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:P00157"
FT BINDING 112
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:P00157"
FT BINDING 197
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:P00157"
FT BINDING 211
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:P00157"
FT BINDING 216
FT /ligand="a ubiquinone"
FT /ligand_id="ChEBI:CHEBI:16389"
FT /evidence="ECO:0000250|UniProtKB:P00157"
SQ SEQUENCE 397 AA; 45597 MW; BBC91638C89B20CD CRC64;
MVGNNTAYNT NAPKSVGPWR STNKLVKIMN DSFYDLPCPV NLNAWWSFGS MLGLCLVIQL
LSGLLLSAHY TAHEDMAFDS VVHIMRNVEK GWMLRNIHAN GSSMFFICIY AHIARGLYYG
SYLDKTVWYF GVHLFLLTMA EAFLGYTLPW GQMSYWGATV ITNMLSVSPV VGESMLRYVW
GGWTVCNATL KRFYTLHFLL PFVMVAVVFL HLFFLHEKGS NNPLGIESGT MCVPFHPFYT
IKDLFGYVCF SFFFMYLVCV DPELLGNHLN YWPANPMKTP IHVQPEWYFM FAYAILRSIP
HKAGGVYVMF LSIVVLYLIP TLHTGKYRSL CFYPLNQVVF WVLVGSFISL TWIGARPVRE
PYIILGSAFQ LFISLVYCWT PFLYGCEMNY LNTLNFV
