ID CYB_SINKE Reviewed; 371 AA. AC Q9MLD7; DT 01-JUN-2001, integrated into UniProtKB/Swiss-Prot. DT 01-OCT-2000, sequence version 1. DT 25-OCT-2017, entry version 78. 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 Sinomicrurus kelloggi (Kellogg's coral snake) (Calliophis kelloggi). OG Mitochondrion. OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; OC Lepidosauria; Squamata; Bifurcata; Unidentata; Episquamata; OC Toxicofera; Serpentes; Colubroidea; Elapidae; Elapinae; Sinomicrurus. OX NCBI_TaxID=114670; RN [1] RP NUCLEOTIDE SEQUENCE [GENOMIC DNA]. RA Slowinski J.B., Boundy J., Lawson R.; RT "The phylogenetic relationships of Asian coral snakes (Elapidae: RT Calliophis and Maticora) based on morphological and molecular RT characters."; RL Submitted (DEC-1999) to the EMBL/GenBank/DDBJ databases. CC -!- FUNCTION: Component of the ubiquinol-cytochrome c reductase CC complex (complex III or cytochrome b-c1 complex) that is part of CC the mitochondrial respiratory chain. The b-c1 complex mediates CC electron transfer from ubiquinol to cytochrome c. Contributes to CC the generation of a proton gradient across the mitochondrial CC membrane that is then used for ATP synthesis. CC {ECO:0000250|UniProtKB:P00157}. CC -!- COFACTOR: CC Name=heme; Xref=ChEBI:CHEBI:30413; CC Evidence={ECO:0000250|UniProtKB:P00157}; CC Note=Binds 2 heme groups non-covalently. CC {ECO:0000250|UniProtKB:P00157}; CC -!- SUBUNIT: The cytochrome bc1 complex contains 3 respiratory CC subunits (MT-CYB, CYC1 and UQCRFS1), 2 core proteins (UQCRC1 and CC UQCRC2) and 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 CC at about 562 nm, and heme 2 (or BH or b566) is high-potential and CC absorbs at about 566 nm. {ECO:0000250}. CC -!- SIMILARITY: Belongs to the cytochrome b family. CC {ECO:0000255|PROSITE-ProRule:PRU00967, 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}. CC --------------------------------------------------------------------------- CC Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms CC Distributed under the Creative Commons Attribution (CC BY 4.0) License CC --------------------------------------------------------------------------- DR EMBL; AF220408; AAF35311.1; -; Genomic_DNA. DR ProteinModelPortal; Q9MLD7; -. DR SMR; Q9MLD7; -. DR HOVERGEN; HBG017694; -. 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:0009055; F:electron carrier activity; 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:0006122; P:mitochondrial electron transport, ubiquinol to cytochrome c; 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. 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; KW Mitochondrion; Mitochondrion inner membrane; Respiratory chain; KW Transmembrane; Transmembrane helix; Transport; Ubiquinone. FT CHAIN 1 371 Cytochrome b. FT /FTId=PRO_0000060708. FT TRANSMEM 25 45 Helical. {ECO:0000250|UniProtKB:P00157}. FT TRANSMEM 69 90 Helical. {ECO:0000250|UniProtKB:P00157}. FT TRANSMEM 105 125 Helical. {ECO:0000250|UniProtKB:P00157}. FT TRANSMEM 170 190 Helical. {ECO:0000250|UniProtKB:P00157}. FT TRANSMEM 218 238 Helical. {ECO:0000250|UniProtKB:P00157}. FT TRANSMEM 280 300 Helical. {ECO:0000250|UniProtKB:P00157}. FT TRANSMEM 312 332 Helical. {ECO:0000250|UniProtKB:P00157}. FT TRANSMEM 339 358 Helical. {ECO:0000250|UniProtKB:P00157}. FT METAL 75 75 Iron 1 (heme b562 axial ligand). FT {ECO:0000250|UniProtKB:P00157}. FT METAL 89 89 Iron 2 (heme b566 axial ligand). FT {ECO:0000250|UniProtKB:P00157}. FT METAL 174 174 Iron 1 (heme b562 axial ligand). FT {ECO:0000250|UniProtKB:P00157}. FT METAL 188 188 Iron 2 (heme b566 axial ligand). FT {ECO:0000250|UniProtKB:P00157}. FT BINDING 193 193 Ubiquinone. FT {ECO:0000250|UniProtKB:P00157}. SQ SEQUENCE 371 AA; 42188 MW; B6723C71E03BD70F CRC64; MSNQHTLLIS NLLPVGSNIS TWWNFGSMLL TCLILQITTG FFLAIHYTAN INLAFSSVTH IMRDVPYGWI MQNLHAIGAS MFFICIYIHI ARGLYYGLYM NKNVWLSGTT LLITLMATAF FGYVLPWGQM SFWAATVITN LLTAIPYLGT TITTWLWGGF SINDPTLTRF FALHFILPFA IISLSSIHII LLHNKGSNNP LGTNSDIDKI PFHPYHSYKD TLMTISLFIL MFTILSFSPD LFNDPENFSK ANPLVTPQHI KPEWYFLFAY GILRSIPNKL GGTLALLMSV TILMTAPFTH TSHMRPMTFR PLAQMAFWTL IATFITITWT ASKPVEPPFI IISQMTSILY FLFFIMNPLL GWTENKIMMN N //