ID   D2KBA1_HUMAN            Unreviewed;        42 AA.
AC   D2KBA1;
DT   09-FEB-2010, integrated into UniProtKB/TrEMBL.
DT   09-FEB-2010, sequence version 1.
DT   02-SEP-2026, entry version 56.
DE   RecName: Full=Cytochrome b {ECO:0000256|ARBA:ARBA00013531};
DE   AltName: Full=Complex III subunit 3 {ECO:0000256|ARBA:ARBA00031681};
DE   AltName: Full=Complex III subunit III {ECO:0000256|ARBA:ARBA00032600};
DE   AltName: Full=Cytochrome b-c1 complex subunit 3 {ECO:0000256|ARBA:ARBA00029812};
DE   AltName: Full=Ubiquinol-cytochrome-c reductase complex cytochrome b subunit {ECO:0000256|ARBA:ARBA00032818};
DE   Flags: Fragment;
OS   Homo sapiens (Human).
OG   Mitochondrion {ECO:0000313|EMBL:ACZ72951.1}.
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia;
OC   Eutheria; Euarchontoglires; Primates; Haplorrhini; Catarrhini; Hominidae;
OC   Homo.
OX   NCBI_TaxID=9606 {ECO:0000313|EMBL:ACZ72951.1};
RN   [1] {ECO:0000313|EMBL:ACZ72951.1}
RP   NUCLEOTIDE SEQUENCE.
RX   PubMed=20454697;
RA   Kumar M., Tanwar M., Saxena R., Sharma P., Dada R.;
RT   "Identification of novel mitochondrial mutations in Leber's hereditary
RT   optic neuropathy.";
RL   Mol. Vis. 16:782-792(2010).
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   -!- 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: Mitochondrion inner membrane
CC       {ECO:0000256|ARBA:ARBA00004448}; Multi-pass membrane protein
CC       {ECO:0000256|ARBA:ARBA00004448}.
CC   -!- SIMILARITY: Belongs to the cytochrome b family. {ECO:0000256|PROSITE-
CC       ProRule:PRU00968}.
CC   -!- CAUTION: Lacks conserved residue(s) required for the propagation of
CC       feature annotation. {ECO:0000256|PROSITE-ProRule:PRU00968}.
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DR   EMBL; GU197846; ACZ72951.1; -; Genomic_DNA.
DR   AlphaFoldDB; D2KBA1; -.
DR   PeptideAtlas; D2KBA1; -.
DR   GO; GO:0005743; C:mitochondrial inner membrane; IEA:UniProtKB-SubCell.
DR   GO; GO:0009055; F:electron transfer activity; IEA:InterPro.
DR   GO; GO:0016491; F:oxidoreductase activity; IEA:InterPro.
DR   GO; GO:0022904; P:respiratory electron transport chain; IEA:InterPro.
DR   Gene3D; 1.20.810.10; Cytochrome Bc1 Complex, Chain C; 1.
DR   InterPro; IPR005797; Cyt_b/b6_N.
DR   InterPro; IPR027387; Cytb/b6-like_sf.
DR   InterPro; IPR016174; Di-haem_cyt_TM.
DR   PANTHER; PTHR19271; CYTOCHROME B; 1.
DR   PANTHER; PTHR19271:SF16; CYTOCHROME B; 1.
DR   Pfam; PF00033; Cytochrome_B; 1.
DR   SUPFAM; SSF81342; Transmembrane di-heme cytochromes; 1.
DR   PROSITE; PS51002; CYTB_NTER; 1.
PE   3: Inferred from homology;
KW   Electron transport {ECO:0000256|ARBA:ARBA00022982, ECO:0000256|PROSITE-
KW   ProRule:PRU00968}; Heme {ECO:0000256|ARBA:ARBA00022617};
KW   Iron {ECO:0000256|ARBA:ARBA00023004};
KW   Membrane {ECO:0000256|ARBA:ARBA00023136, ECO:0000256|PROSITE-
KW   ProRule:PRU00968}; Metal-binding {ECO:0000256|ARBA:ARBA00022723};
KW   Mitochondrion {ECO:0000256|ARBA:ARBA00023128, ECO:0000313|EMBL:ACZ72951.1};
KW   Mitochondrion inner membrane {ECO:0000256|ARBA:ARBA00022792};
KW   Respiratory chain {ECO:0000256|ARBA:ARBA00022660};
KW   Transmembrane {ECO:0000256|ARBA:ARBA00022692, ECO:0000256|PROSITE-
KW   ProRule:PRU00968};
KW   Transmembrane helix {ECO:0000256|ARBA:ARBA00022989, ECO:0000256|PROSITE-
KW   ProRule:PRU00968};
KW   Transport {ECO:0000256|ARBA:ARBA00022448, ECO:0000256|PROSITE-
KW   ProRule:PRU00968}; Ubiquinone {ECO:0000256|ARBA:ARBA00023075}.
FT   DOMAIN          1..42
FT                   /note="Cytochrome b/b6 N-terminal region profile"
FT                   /evidence="ECO:0000259|PROSITE:PS51002"
FT   NON_TER         1
FT                   /evidence="ECO:0000313|EMBL:ACZ72951.1"
FT   NON_TER         42
FT                   /evidence="ECO:0000313|EMBL:ACZ72951.1"
SQ   SEQUENCE   42 AA;  4746 MW;  7499EEE6EB004C65 CRC64;
     LFLAMHYSPD ASTAFSSIAH ITRDVNYGWI IRYLHANGAS MF
//