ID CYB6_CHAGL Reviewed; 215 AA. AC Q8M9Z4; DT 11-APR-2003, integrated into UniProtKB/Swiss-Prot. DT 01-OCT-2002, sequence version 1. DT 15-FEB-2017, entry version 78. DE RecName: Full=Cytochrome b6 {ECO:0000255|HAMAP-Rule:MF_00633}; GN Name=petB {ECO:0000255|HAMAP-Rule:MF_00633}; OS Chaetosphaeridium globosum (Charophycean green alga) (Herposteiron OS globosum). OG Plastid; Chloroplast. OC Eukaryota; Viridiplantae; Streptophyta; Coleochaetophyceae; OC Coleochaetales; Chaetosphaeridiaceae; Chaetosphaeridium. OX NCBI_TaxID=96477; RN [1] RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. RC STRAIN=M1311; RX PubMed=12161560; DOI=10.1073/pnas.162203299; RA Turmel M., Otis C., Lemieux C.; RT "The chloroplast and mitochondrial genome sequences of the charophyte RT Chaetosphaeridium globosum: insights into the timing of the events RT that restructured organelle DNAs within the green algal lineage that RT led to land plants."; RL Proc. Natl. Acad. Sci. U.S.A. 99:11275-11280(2002). CC -!- FUNCTION: Component of the cytochrome b6-f complex, which mediates CC electron transfer between photosystem II (PSII) and photosystem I CC (PSI), cyclic electron flow around PSI, and state transitions. CC {ECO:0000255|HAMAP-Rule:MF_00633}. CC -!- COFACTOR: CC Name=heme; Xref=ChEBI:CHEBI:30413; CC Evidence={ECO:0000255|HAMAP-Rule:MF_00633}; CC Note=Binds 2 heme groups. One heme group is bound covalently by a CC single cysteine link, the other one non-covalently. CC {ECO:0000255|HAMAP-Rule:MF_00633}; CC -!- SUBUNIT: The 4 large subunits of the cytochrome b6-f complex are CC cytochrome b6, subunit IV (17 kDa polypeptide, PetD), cytochrome f CC and the Rieske protein, while the 4 small subunits are PetG, PetL, CC PetM and PetN. The complex functions as a dimer. CC {ECO:0000255|HAMAP-Rule:MF_00633}. CC -!- SUBCELLULAR LOCATION: Plastid, chloroplast thylakoid membrane CC {ECO:0000255|HAMAP-Rule:MF_00633}; Multi-pass membrane protein CC {ECO:0000255|HAMAP-Rule:MF_00633}. CC -!- MISCELLANEOUS: Heme 1 (or BH or b566) is high-potential and CC absorbs at about 566 nm, and heme 2 (or BL or b562) is low- CC potential and absorbs at about 562 nm. {ECO:0000255|HAMAP- CC Rule:MF_00633}. CC -!- SIMILARITY: Belongs to the cytochrome b family. PetB subfamily. CC {ECO:0000255|HAMAP-Rule:MF_00633}. 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; AF494278; AAM96527.1; -; Genomic_DNA. DR RefSeq; NP_683792.1; NC_004115.1. DR ProteinModelPortal; Q8M9Z4; -. DR GeneID; 860809; -. DR GO; GO:0009535; C:chloroplast thylakoid membrane; IEA:UniProtKB-SubCell. DR GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW. DR GO; GO:0045158; F:electron transporter, transferring electrons within cytochrome b6/f complex of photosystem II activity; IEA:InterPro. DR GO; GO:0020037; F:heme binding; IEA:InterPro. DR GO; GO:0005506; F:iron ion binding; IEA:InterPro. DR GO; GO:0016491; F:oxidoreductase activity; IEA:InterPro. DR GO; GO:0015979; P:photosynthesis; 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 HAMAP; MF_00633; Cytb6_f_cytb6; 1. DR InterPro; IPR005797; Cyt_b/b6_N. DR InterPro; IPR023530; Cyt_B6_PetB. DR InterPro; IPR027387; Cytb/b6-like. DR InterPro; IPR016174; Di-haem_cyt_TM. DR Pfam; PF00033; Cytochrome_B; 1. DR PIRSF; PIRSF000032; Cytochrome_b6; 1. DR SUPFAM; SSF81342; SSF81342; 1. DR PROSITE; PS51002; CYTB_NTER; 1. PE 3: Inferred from homology; KW Chloroplast; Electron transport; Heme; Iron; Membrane; Metal-binding; KW Photosynthesis; Plastid; Thylakoid; Transmembrane; KW Transmembrane helix; Transport. FT CHAIN 1 215 Cytochrome b6. FT /FTId=PRO_0000061785. FT TRANSMEM 32 52 Helical. {ECO:0000255|HAMAP- FT Rule:MF_00633}. FT TRANSMEM 90 110 Helical. {ECO:0000255|HAMAP- FT Rule:MF_00633}. FT TRANSMEM 116 136 Helical. {ECO:0000255|HAMAP- FT Rule:MF_00633}. FT TRANSMEM 186 206 Helical. {ECO:0000255|HAMAP- FT Rule:MF_00633}. FT METAL 86 86 Iron (heme 2 axial ligand). FT {ECO:0000255|HAMAP-Rule:MF_00633}. FT METAL 100 100 Iron (heme 1 axial ligand). FT {ECO:0000255|HAMAP-Rule:MF_00633}. FT METAL 187 187 Iron (heme 2 axial ligand). FT {ECO:0000255|HAMAP-Rule:MF_00633}. FT METAL 202 202 Iron (heme 1 axial ligand). FT {ECO:0000255|HAMAP-Rule:MF_00633}. FT BINDING 35 35 Heme 1 (covalent; via 1 link). FT {ECO:0000255|HAMAP-Rule:MF_00633}. SQ SEQUENCE 215 AA; 24231 MW; 2879F90589E0DDFA CRC64; MGKVYDWFEE RLEIQAIADD ISSKYVPPHV NIFYCLGGIT FTSFVIQVAS GFAMTFYYRP TVTEAFASVQ YIMTEVNFGW LIRSVHRWSA SMMVLMMILH IFRVYLTGGF KKPRELTWVT GVILSVLTVS FGVTGYSLPW DQVGYWAVKI VTGVPDAIPV IGSTVVELLR GSVSVGQSTL TRFYSLHTFV LPLLTAVFML MHFLMIRKQG ISGPL //