CYB_AMBTI
ID CYB_AMBTI Reviewed; 102 AA.
AC P34860;
DT 01-FEB-1994, integrated into UniProtKB/Swiss-Prot.
DT 01-NOV-1997, sequence version 2.
DT 03-AUG-2022, entry version 97.
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;
DE Flags: Fragment;
GN Name=mt-cyb; Synonyms=cob, cytb, mtcyb;
OS Ambystoma tigrinum (Eastern tiger salamander).
OG Mitochondrion.
OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Amphibia;
OC Batrachia; Caudata; Salamandroidea; Ambystomatidae; Ambystoma.
OX NCBI_TaxID=8305;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC STRAIN=Various isolates;
RX PubMed=1570014; DOI=10.1038/356708a0;
RA Hedges S.B., Bogart J.P., Maxson L.R.;
RT "Ancestry of unisexual salamanders.";
RL Nature 356:708-710(1992).
RN [2]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 15-89.
RX PubMed=2762322; DOI=10.1073/pnas.86.16.6196;
RA Kocher T.D., Thomas W.K., Meyer A., Edwards S.V., Paeaebo S.,
RA Villablanca F.X., Wilson A.C.;
RT "Dynamics of mitochondrial DNA evolution in animals: amplification and
RT sequencing with conserved primers.";
RL Proc. Natl. Acad. Sci. U.S.A. 86:6196-6200(1989).
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 cytochrome bc1 complex contains 3 respiratory subunits
CC (MT-CYB, CYC1 and UQCRFS1), 2 core proteins (UQCRC1 and UQCRC2) and
CC probably 6 low-molecular weight proteins.
CC {ECO:0000250|UniProtKB:P00157}.
CC -!- SUBCELLULAR LOCATION: Mitochondrion inner membrane
CC {ECO:0000250|UniProtKB:P00157}; Multi-pass membrane protein
CC {ECO:0000250|UniProtKB:P00157}.
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: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; Z11627; CAA77702.1; -; Genomic_DNA.
DR EMBL; Z11628; CAA77703.1; -; Genomic_DNA.
DR EMBL; Z11631; CAA77706.1; -; Genomic_DNA.
DR EMBL; Z11632; CAA77707.1; -; Genomic_DNA.
DR EMBL; Z11634; CAA77709.1; -; Genomic_DNA.
DR EMBL; Z11635; CAA77710.1; -; Genomic_DNA.
DR EMBL; Z11636; CAA77711.1; -; Genomic_DNA.
DR EMBL; Z11637; CAA77712.1; -; Genomic_DNA.
DR EMBL; Z11638; CAA77713.1; -; Genomic_DNA.
DR EMBL; Z11639; CAA77714.1; -; Genomic_DNA.
DR EMBL; Z11640; CAA77715.1; -; Genomic_DNA.
DR EMBL; Z11645; CAA77720.1; -; Genomic_DNA.
DR EMBL; Z11648; CAA77723.1; -; Genomic_DNA.
DR EMBL; Z11659; CAA77728.1; -; Genomic_DNA.
DR EMBL; M26230; AAA31635.1; -; Genomic_DNA.
DR AlphaFoldDB; P34860; -.
DR SMR; P34860; -.
DR GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
DR GO; GO:0005743; C:mitochondrial inner membrane; IEA:UniProtKB-SubCell.
DR GO; GO:0070469; C:respirasome; IEA:UniProtKB-KW.
DR GO; GO:0009055; F:electron transfer activity; IEA:InterPro.
DR GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR GO; GO:0022904; P:respiratory electron transport chain; IEA:InterPro.
DR Gene3D; 1.20.810.10; -; 1.
DR InterPro; IPR005797; Cyt_b/b6_N.
DR InterPro; IPR027387; Cytb/b6-like_sf.
DR InterPro; IPR016174; Di-haem_cyt_TM.
DR Pfam; PF00033; Cytochrome_B; 1.
DR SUPFAM; SSF81342; SSF81342; 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..>102
FT /note="Cytochrome b"
FT /id="PRO_0000060572"
FT TRANSMEM 1..21
FT /note="Helical"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00968"
FT TRANSMEM 45..66
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00157"
FT TRANSMEM 81..101
FT /note="Helical"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00968"
FT BINDING 51
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 65
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 NON_TER 1
FT NON_TER 102
SQ SEQUENCE 102 AA; 11433 MW; 3E98ABCA09177335 CRC64;
FGSLLGLCLI TQILTGLFLA MHYTADTSSA FSSVAHICRD VNYGWLMRNI HANGASFFFI
CIFLHIGRGM YYGSYMFKET WNIGVILLFL VMATAFVGYV LP
