CYB_LEITA
ID CYB_LEITA Reviewed; 371 AA.
AC P14548;
DT 01-JAN-1990, integrated into UniProtKB/Swiss-Prot.
DT 01-APR-1990, sequence version 2.
DT 03-AUG-2022, entry version 100.
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 Leishmania tarentolae (Sauroleishmania tarentolae).
OG Mitochondrion.
OC Eukaryota; Discoba; Euglenozoa; Kinetoplastea; Metakinetoplastina;
OC Trypanosomatida; Trypanosomatidae; Leishmaniinae; Leishmania;
OC lizard Leishmania.
OX NCBI_TaxID=5689;
RN [1]
RP NUCLEOTIDE SEQUENCE [MRNA], AND RNA EDITING.
RX PubMed=2452696; DOI=10.1016/0092-8674(88)90160-2;
RA Shaw J.M., Feagin J.E., Stuart K.D., Simpson L.;
RT "Editing of kinetoplastid mitochondrial mRNAs by uridine addition and
RT deletion generates conserved amino acid sequences and AUG initiation
RT codons.";
RL Cell 53:401-411(1988).
RN [2]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX PubMed=2994021; DOI=10.1093/nar/13.16.5977;
RA Simpson A.M., Necklemann N., la Cruz V.F., Muhich M.L., Simpson L.;
RT "Mapping and 5' end determination of kinetoplast maxicircle gene
RT transcripts from Leishmania tarentolae.";
RL Nucleic Acids Res. 13:5977-5993(1985).
RN [3]
RP NUCLEOTIDE SEQUENCE [MRNA] OF 1-48, AND RNA EDITING.
RX PubMed=2448777; DOI=10.1073/pnas.85.2.539;
RA Feagin J.E., Shaw J.M., Simpson L., Stuart K.;
RT "Creation of AUG initiation codons by addition of uridines within
RT cytochrome b transcripts of kinetoplastids.";
RL Proc. Natl. Acad. Sci. U.S.A. 85:539-543(1988).
RN [4]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 21-371.
RX PubMed=6096360; DOI=10.1016/s0021-9258(17)42525-7;
RA de la Cruz V.F., Neckelmann N., Simpson L.;
RT "Sequences of six genes and several open reading frames in the kinetoplast
RT maxicircle DNA of Leishmania tarentolae.";
RL J. Biol. Chem. 259:15136-15147(1984).
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: The main subunits of complex b-c1 are: cytochrome b,
CC cytochrome c1 and the Rieske protein. {ECO:0000250}.
CC -!- SUBCELLULAR LOCATION: Mitochondrion inner membrane
CC {ECO:0000250|UniProtKB:P00163}; Multi-pass membrane protein
CC {ECO:0000250|UniProtKB:P00163}.
CC -!- RNA EDITING: Modified_positions=Not_applicable; Note=Some positions are
CC modified by RNA editing via nucleotide insertion or deletion. The
CC initiator methionine is created by RNA editing.
CC {ECO:0000269|PubMed:2448777, ECO:0000269|PubMed:2452696};
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 an even number of transmembrane helices,
CC fewer than predicted by bioinformatics tools.
CC {ECO:0000250|UniProtKB:P00163}.
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DR EMBL; L07542; AAA31879.1; ALT_SEQ; mRNA.
DR EMBL; M10126; -; NOT_ANNOTATED_CDS; Genomic_DNA.
DR EMBL; M19065; AAA31878.1; -; mRNA.
DR PIR; H22848; H22848.
DR AlphaFoldDB; P14548; -.
DR SMR; P14548; -.
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 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; IPR016174; Di-haem_cyt_TM.
DR Pfam; PF00032; Cytochrom_B_C; 1.
DR Pfam; PF00033; Cytochrome_B; 1.
DR SUPFAM; SSF81342; SSF81342; 1.
DR SUPFAM; SSF81648; SSF81648; 1.
DR PROSITE; PS51003; CYTB_CTER; 1.
DR PROSITE; PS51002; CYTB_NTER; 1.
PE 2: Evidence at transcript level;
KW Electron transport; Heme; Iron; Membrane; Metal-binding; Mitochondrion;
KW Mitochondrion inner membrane; Respiratory chain; RNA editing;
KW Transmembrane; Transmembrane helix; Transport; Ubiquinone.
FT CHAIN 1..371
FT /note="Cytochrome b"
FT /id="PRO_0000061094"
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 227..247
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P00163"
FT TRANSMEM 296..316
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TRANSMEM 329..349
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TRANSMEM 350..370
FT /note="Helical"
FT /evidence="ECO:0000255"
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:0000250|UniProtKB:P00163"
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:0000250|UniProtKB:P00163"
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:0000250|UniProtKB:P00163"
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:0000250|UniProtKB:P00163"
FT BINDING 202
FT /ligand="a ubiquinone"
FT /ligand_id="ChEBI:CHEBI:16389"
FT /evidence="ECO:0000250|UniProtKB:P00157"
SQ SEQUENCE 371 AA; 44555 MW; 0003BD11538EA75B CRC64;
MFFRVRFLLF FLLFRNLCCL LTSGCLLRVY GVGFSLGFFI CMQIICGVCL AWLFFSCFIC
TNWYFVLFLW DFDLGFVIRS THICFTSLLF FLLYVHIFKC IVLIILFDTH ILVWAVGFII
YIFIVVIGFI GYVLPCTMMS YWGLTVFSNI LATVPVIGTW LCYWIWGSEY INDFTLLKLH
VLHVLLPFVL ILVIFMHLFC LHYFMSSDGF CDRFAFYCER LCFCMWFYLR DMFLAFLILF
YVVYFIFINW YFVFHEESWV IVDTLKTSDK ILPEWFFLFL FGFLKAVPDK FTGLLLMVIL
LFSLFLFILN CILWFVYCRS SLLWFTYSLI LFYSIFMSGF LALYVILAYP IWMELQFWVL
LLFMLVVCRL D
