ID   A6YVI1_HUMAN            Unreviewed;       378 AA.
AC   A6YVI1;
DT   21-AUG-2007, integrated into UniProtKB/TrEMBL.
DT   21-AUG-2007, sequence version 1.
DT   27-MAR-2024, entry version 99.
DE   RecName: Full=Cytochrome b {ECO:0000256|ARBA:ARBA00013531, ECO:0000256|RuleBase:RU362117};
GN   Name=CYTB {ECO:0000313|EMBL:ABR93711.1};
OS   Homo sapiens (Human).
OG   Mitochondrion {ECO:0000313|EMBL:ABR93711.1}.
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia;
OC   Eutheria; Euarchontoglires; Primates; Haplorrhini; Catarrhini; Hominidae;
OC   Homo.
OX   NCBI_TaxID=9606 {ECO:0000313|EMBL:ABR93711.1};
RN   [1] {ECO:0000313|EMBL:ABR93711.1}
RP   NUCLEOTIDE SEQUENCE.
RC   STRAIN=MTDNA15 {ECO:0000313|EMBL:ABR93711.1}, MTDNA286
RC   {ECO:0000313|EMBL:ABR95669.1}, MTDNA341 {ECO:0000313|EMBL:ABR96473.1},
RC   MTDNA412 {ECO:0000313|EMBL:ABR97498.1}, MTDNA475
RC   {ECO:0000313|EMBL:ABR98394.1}, MTDNA525 {ECO:0000313|EMBL:ABR99121.1},
RC   and MTDNA526 {ECO:0000313|EMBL:ABR99134.1};
RX   PubMed=11938495; DOI=10.1086/339933;
RA   Herrnstadt C., Elson J.L., Fahy E., Preston G., Turnbull D.M., Anderson C.,
RA   Ghosh S.S., Olefsky J.M., Beal M.F., Davis R.E., Howell N.;
RT   "Reduced-median-network analysis of complete mitochondrial DNA coding-
RT   region sequences for the major African, Asian, and European haplogroups.";
RL   Am. J. Hum. Genet. 70:1152-1171(2002).
RN   [2] {ECO:0000313|EMBL:ABR93711.1}
RP   NUCLEOTIDE SEQUENCE.
RC   STRAIN=MTDNA15 {ECO:0000313|EMBL:ABR93711.1}, MTDNA286
RC   {ECO:0000313|EMBL:ABR95669.1}, MTDNA341 {ECO:0000313|EMBL:ABR96473.1},
RC   MTDNA412 {ECO:0000313|EMBL:ABR97498.1}, MTDNA475
RC   {ECO:0000313|EMBL:ABR98394.1}, MTDNA525 {ECO:0000313|EMBL:ABR99121.1},
RC   and MTDNA526 {ECO:0000313|EMBL:ABR99134.1};
RA   Herrnstadt C., Fahy E., Preston G., Anderson C., Ghosh S.S., Davis R.E.,
RA   Howell N.;
RL   Submitted (JUN-2007) to the EMBL/GenBank/DDBJ databases.
RN   [3] {ECO:0000313|EMBL:ABR93711.1}
RP   NUCLEOTIDE SEQUENCE.
RC   STRAIN=MTDNA15 {ECO:0000313|EMBL:ABR93711.1}, MTDNA286
RC   {ECO:0000313|EMBL:ABR95669.1}, MTDNA341 {ECO:0000313|EMBL:ABR96473.1},
RC   MTDNA412 {ECO:0000313|EMBL:ABR97498.1}, MTDNA475
RC   {ECO:0000313|EMBL:ABR98394.1}, MTDNA525 {ECO:0000313|EMBL:ABR99121.1},
RC   and MTDNA526 {ECO:0000313|EMBL:ABR99134.1};
RG   HmtDB;
RL   Submitted (JUN-2007) to the EMBL/GenBank/DDBJ databases.
RN   [4] {ECO:0000313|EMBL:AQU13452.1}
RP   NUCLEOTIDE SEQUENCE.
RX   PubMed=28177087; DOI=.1093/molbev/msx082;
RA   Olivieri A., Sidore C., Achilli A., Angius A., Posth C., Furtwangler A.,
RA   Brandini S., Rosario Capodiferro M., Gandini F., Zoledziewska M.,
RA   Pitzalis M., Maschio A., Busonero F., Lai L., Skeates R.,
RA   Giuseppina Gradoli M., Beckett J., Marongiu M., Mazzarello V., Marongiu P.,
RA   Rubino S., Rito T., Macaulay V., Semino O., Pala M., Abecasis G.R.,
RA   Schlessinger D., Conde-Sousa E., Soares P., Richards M.B., Cucca F.,
RA   Torroni A.;
RT   "Mitogenome Diversity in Sardinians: A Genetic Window onto an Island's
RT   Past.";
RL   Mol. Biol. Evol. 34:1230-1239(2017).
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:0000256|ARBA:ARBA00002566,
CC       ECO:0000256|RuleBase:RU362117}.
CC   -!- COFACTOR:
CC       Name=heme b; Xref=ChEBI:CHEBI:60344;
CC         Evidence={ECO:0000256|RuleBase:RU362117};
CC       Note=Binds 2 heme groups non-covalently.
CC       {ECO:0000256|RuleBase:RU362117};
CC   -!- COFACTOR:
CC       Name=heme; Xref=ChEBI:CHEBI:30413;
CC         Evidence={ECO:0000256|PIRSR:PIRSR038885-2};
CC       Note=Binds 2 heme groups non-covalently.
CC       {ECO:0000256|PIRSR:PIRSR038885-2};
CC   -!- SUBUNIT: The cytochrome bc1 complex contains 11 subunits: 3 respiratory
CC       subunits (MT-CYB, CYC1 and UQCRFS1), 2 core proteins (UQCRC1 and
CC       UQCRC2) and 6 low-molecular weight proteins (UQCRH/QCR6, UQCRB/QCR7,
CC       UQCRQ/QCR8, UQCR10/QCR9, UQCR11/QCR10 and a cleavage product of
CC       UQCRFS1). This cytochrome bc1 complex then forms a dimer.
CC       {ECO:0000256|ARBA:ARBA00011088}.
CC   -!- SUBCELLULAR LOCATION: Membrane {ECO:0000256|ARBA:ARBA00004141}; Multi-
CC       pass membrane protein {ECO:0000256|ARBA:ARBA00004141}. Mitochondrion
CC       inner membrane {ECO:0000256|ARBA:ARBA00004448}; Multi-pass membrane
CC       protein {ECO:0000256|ARBA:ARBA00004448}.
CC   -!- SIMILARITY: Belongs to the cytochrome b family.
CC       {ECO:0000256|RuleBase:RU362117}.
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DR   EMBL; EF657287; ABR93711.1; -; Genomic_DNA.
DR   EMBL; EF657438; ABR95669.1; -; Genomic_DNA.
DR   EMBL; EF657500; ABR96473.1; -; Genomic_DNA.
DR   EMBL; EF657579; ABR97498.1; -; Genomic_DNA.
DR   EMBL; EF657648; ABR98394.1; -; Genomic_DNA.
DR   EMBL; EF657704; ABR99121.1; -; Genomic_DNA.
DR   EMBL; EF657705; ABR99134.1; -; Genomic_DNA.
DR   EMBL; KY399171; AQU13452.1; -; Genomic_DNA.
DR   AlphaFoldDB; A6YVI1; -.
DR   PeptideAtlas; A6YVI1; -.
DR   ChiTaRS; CYTB; human.
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-UniRule.
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   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; IPR048260; Cytochrome_b_C_euk/bac.
DR   InterPro; IPR048259; Cytochrome_b_N_euk/bac.
DR   InterPro; IPR016174; Di-haem_cyt_TM.
DR   PANTHER; PTHR19271; CYTOCHROME B; 1.
DR   PANTHER; PTHR19271:SF16; CYTOCHROME B; 1.
DR   Pfam; PF00032; Cytochrom_B_C; 1.
DR   Pfam; PF00033; Cytochrome_B; 1.
DR   PIRSF; PIRSF038885; COB; 1.
DR   SUPFAM; SSF81648; a domain/subunit of cytochrome bc1 complex (Ubiquinol-cytochrome c reductase); 1.
DR   SUPFAM; SSF81342; Transmembrane di-heme cytochromes; 1.
DR   PROSITE; PS51003; CYTB_CTER; 1.
DR   PROSITE; PS51002; CYTB_NTER; 1.
PE   3: Inferred from homology;
KW   Electron transport {ECO:0000256|ARBA:ARBA00022982,
KW   ECO:0000256|RuleBase:RU362117};
KW   Heme {ECO:0000256|ARBA:ARBA00022617, ECO:0000256|PIRSR:PIRSR038885-2};
KW   Iron {ECO:0000256|ARBA:ARBA00023004, ECO:0000256|PIRSR:PIRSR038885-2};
KW   Membrane {ECO:0000256|ARBA:ARBA00023136, ECO:0000256|RuleBase:RU362117};
KW   Metal-binding {ECO:0000256|ARBA:ARBA00022723,
KW   ECO:0000256|PIRSR:PIRSR038885-2};
KW   Mitochondrion {ECO:0000256|ARBA:ARBA00023128,
KW   ECO:0000256|RuleBase:RU362117};
KW   Mitochondrion inner membrane {ECO:0000256|ARBA:ARBA00022792};
KW   Respiratory chain {ECO:0000256|ARBA:ARBA00022660,
KW   ECO:0000256|RuleBase:RU362117};
KW   Transmembrane {ECO:0000256|ARBA:ARBA00022692,
KW   ECO:0000256|RuleBase:RU362117};
KW   Transmembrane helix {ECO:0000256|ARBA:ARBA00022989,
KW   ECO:0000256|RuleBase:RU362117};
KW   Transport {ECO:0000256|ARBA:ARBA00022448, ECO:0000256|RuleBase:RU362117};
KW   Ubiquinone {ECO:0000256|ARBA:ARBA00023075}.
FT   TRANSMEM        30..56
FT                   /note="Helical"
FT                   /evidence="ECO:0000256|RuleBase:RU362117"
FT   TRANSMEM        77..98
FT                   /note="Helical"
FT                   /evidence="ECO:0000256|RuleBase:RU362117"
FT   TRANSMEM        113..133
FT                   /note="Helical"
FT                   /evidence="ECO:0000256|RuleBase:RU362117"
FT   TRANSMEM        140..158
FT                   /note="Helical"
FT                   /evidence="ECO:0000256|RuleBase:RU362117"
FT   TRANSMEM        178..200
FT                   /note="Helical"
FT                   /evidence="ECO:0000256|RuleBase:RU362117"
FT   TRANSMEM        229..246
FT                   /note="Helical"
FT                   /evidence="ECO:0000256|RuleBase:RU362117"
FT   TRANSMEM        288..308
FT                   /note="Helical"
FT                   /evidence="ECO:0000256|RuleBase:RU362117"
FT   TRANSMEM        320..339
FT                   /note="Helical"
FT                   /evidence="ECO:0000256|RuleBase:RU362117"
FT   TRANSMEM        345..372
FT                   /note="Helical"
FT                   /evidence="ECO:0000256|RuleBase:RU362117"
FT   DOMAIN          1..209
FT                   /note="Cytochrome b/b6 N-terminal region profile"
FT                   /evidence="ECO:0000259|PROSITE:PS51002"
FT   DOMAIN          210..378
FT                   /note="Cytochrome b/b6 C-terminal region profile"
FT                   /evidence="ECO:0000259|PROSITE:PS51003"
FT   BINDING         83
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:0000256|PIRSR:PIRSR038885-2"
FT   BINDING         97
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:0000256|PIRSR:PIRSR038885-2"
FT   BINDING         182
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:0000256|PIRSR:PIRSR038885-2"
FT   BINDING         196
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:0000256|PIRSR:PIRSR038885-2"
FT   BINDING         201
FT                   /ligand="a ubiquinone"
FT                   /ligand_id="ChEBI:CHEBI:16389"
FT                   /evidence="ECO:0000256|PIRSR:PIRSR038885-1"
SQ   SEQUENCE   378 AA;  42460 MW;  720C262E54980879 CRC64;
     MTPMRKTNPL MKLINHSFID LPTPSNISAW WNFGSLLGAC LILQITTGLF LAMHYSPDAS
     TAFSSIAHIT RDVNYGWIIR YLHANGASMF FICLFLHIGR GLYYGSFLYS ETWNIGIILL
     LATMATAFMG YVLPWGQMSF WGATVITNLL SAIPYIGTDL VQWIWGGYSV DSPTLTRFFT
     FHFILPFIIA ALATLHLLFL HETGSNNPLG ITSHSDKITF HPYYTIKDAL GLLLFLLSLM
     TLTLFSPDLL GDPDNYTLAN PLNTPPHIKP EWYFLFAYTI LRSVPNKLGG VLALLLSILI
     LAMIPILHMS KQQSMMFRPL SQSLYWLLAA DLLILTWIGG QPVSYPFTII GQVASVLYFT
     TILILMPTIS LIENKMLK
//