ID K9QX34_NOSS7 Unreviewed; 215 AA.
AC K9QX34;
DT 06-MAR-2013, integrated into UniProtKB/TrEMBL.
DT 06-MAR-2013, sequence version 1.
DT 27-MAR-2024, entry version 59.
DE RecName: Full=Cytochrome b6 {ECO:0000256|ARBA:ARBA00035697, ECO:0000256|HAMAP-Rule:MF_00633};
GN Name=petB {ECO:0000256|HAMAP-Rule:MF_00633};
GN OrderedLocusNames=Nos7524_3958 {ECO:0000313|EMBL:AFY49731.1};
OS Nostoc sp. (strain ATCC 29411 / PCC 7524).
OC Bacteria; Cyanobacteriota; Cyanophyceae; Nostocales; Nostocaceae; Nostoc.
OX NCBI_TaxID=28072 {ECO:0000313|EMBL:AFY49731.1, ECO:0000313|Proteomes:UP000010378};
RN [1] {ECO:0000313|Proteomes:UP000010378}
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=ATCC 29411 / PCC 7524 {ECO:0000313|Proteomes:UP000010378};
RX PubMed=23277585; DOI=10.1073/pnas.1217107110;
RA Shih P.M., Wu D., Latifi A., Axen S.D., Fewer D.P., Talla E., Calteau A.,
RA Cai F., Tandeau de Marsac N., Rippka R., Herdman M., Sivonen K.,
RA Coursin T., Laurent T., Goodwin L., Nolan M., Davenport K.W., Han C.S.,
RA Rubin E.M., Eisen J.A., Woyke T., Gugger M., Kerfeld C.A.;
RT "Improving the coverage of the cyanobacterial phylum using diversity-driven
RT genome sequencing.";
RL Proc. Natl. Acad. Sci. U.S.A. 110:1053-1058(2013).
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:0000256|ARBA:ARBA00003068, ECO:0000256|HAMAP-Rule:MF_00633}.
CC -!- COFACTOR:
CC Name=heme b; Xref=ChEBI:CHEBI:60344;
CC Evidence={ECO:0000256|HAMAP-Rule:MF_00633};
CC Note=Binds 2 heme b groups non-covalently with two histidine residues
CC as axial ligands. {ECO:0000256|HAMAP-Rule:MF_00633};
CC -!- COFACTOR:
CC Name=heme c; Xref=ChEBI:CHEBI:61717;
CC Evidence={ECO:0000256|HAMAP-Rule:MF_00633};
CC Note=Binds one heme group covalently by a single cysteine link with no
CC axial amino acid ligand. This heme was named heme ci.
CC {ECO:0000256|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 and
CC the Rieske protein, while the 4 small subunits are PetG, PetL, PetM and
CC PetN. The complex functions as a dimer. {ECO:0000256|ARBA:ARBA00025834,
CC ECO:0000256|HAMAP-Rule:MF_00633}.
CC -!- SUBCELLULAR LOCATION: Cellular thylakoid membrane {ECO:0000256|HAMAP-
CC Rule:MF_00633}; Multi-pass membrane protein {ECO:0000256|HAMAP-
CC Rule:MF_00633}. Membrane {ECO:0000256|ARBA:ARBA00004141}; Multi-pass
CC membrane protein {ECO:0000256|ARBA:ARBA00004141}.
CC -!- MISCELLANEOUS: Heme 1 (or BH or b566) is high-potential and absorbs at
CC about 566 nm, and heme 2 (or BL or b562) is low-potential and absorbs
CC at about 562 nm. {ECO:0000256|HAMAP-Rule:MF_00633}.
CC -!- SIMILARITY: Belongs to the cytochrome b family. PetB subfamily.
CC {ECO:0000256|HAMAP-Rule:MF_00633}.
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DR EMBL; CP003552; AFY49731.1; -; Genomic_DNA.
DR RefSeq; WP_010997571.1; NC_019684.1.
DR AlphaFoldDB; K9QX34; -.
DR SMR; K9QX34; -.
DR STRING; 28072.Nos7524_3958; -.
DR GeneID; 58726228; -.
DR KEGG; nop:Nos7524_3958; -.
DR PATRIC; fig|28072.8.peg.4330; -.
DR eggNOG; COG1290; Bacteria.
DR HOGENOM; CLU_031114_0_2_3; -.
DR OrthoDB; 9804503at2; -.
DR Proteomes; UP000010378; Chromosome.
DR GO; GO:0031676; C:plasma membrane-derived thylakoid membrane; IEA:UniProtKB-SubCell.
DR GO; GO:0045158; F:electron transporter, transferring electrons within cytochrome b6/f complex of photosystem II activity; IEA:UniProtKB-UniRule.
DR GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR GO; GO:0015979; P:photosynthesis; IEA:UniProtKB-UniRule.
DR GO; GO:0022904; P:respiratory electron transport chain; IEA:InterPro.
DR CDD; cd00284; Cytochrome_b_N; 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_sf.
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; PF00033; Cytochrome_B; 1.
DR PIRSF; PIRSF000032; Cytochrome_b6; 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|HAMAP-Rule:MF_00633};
KW Heme {ECO:0000256|HAMAP-Rule:MF_00633};
KW Iron {ECO:0000256|HAMAP-Rule:MF_00633};
KW Membrane {ECO:0000256|HAMAP-Rule:MF_00633, ECO:0000256|SAM:Phobius};
KW Metal-binding {ECO:0000256|HAMAP-Rule:MF_00633};
KW Photosynthesis {ECO:0000256|ARBA:ARBA00022531, ECO:0000256|HAMAP-
KW Rule:MF_00633}; Reference proteome {ECO:0000313|Proteomes:UP000010378};
KW Thylakoid {ECO:0000256|HAMAP-Rule:MF_00633};
KW Transmembrane {ECO:0000256|HAMAP-Rule:MF_00633, ECO:0000256|SAM:Phobius};
KW Transmembrane helix {ECO:0000256|HAMAP-Rule:MF_00633,
KW ECO:0000256|SAM:Phobius}; Transport {ECO:0000256|HAMAP-Rule:MF_00633}.
FT TRANSMEM 32..58
FT /note="Helical"
FT /evidence="ECO:0000256|SAM:Phobius"
FT TRANSMEM 88..106
FT /note="Helical"
FT /evidence="ECO:0000256|SAM:Phobius"
FT TRANSMEM 118..138
FT /note="Helical"
FT /evidence="ECO:0000256|SAM:Phobius"
FT TRANSMEM 184..206
FT /note="Helical"
FT /evidence="ECO:0000256|SAM:Phobius"
FT DOMAIN 4..215
FT /note="Cytochrome b/b6 N-terminal region profile"
FT /evidence="ECO:0000259|PROSITE:PS51002"
FT BINDING 35
FT /ligand="heme c"
FT /ligand_id="ChEBI:CHEBI:61717"
FT /note="covalent"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_00633"
FT BINDING 86
FT /ligand="heme b"
FT /ligand_id="ChEBI:CHEBI:60344"
FT /ligand_label="2"
FT /ligand_part="Fe"
FT /ligand_part_id="ChEBI:CHEBI:18248"
FT /note="axial binding residue"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_00633"
FT BINDING 100
FT /ligand="heme b"
FT /ligand_id="ChEBI:CHEBI:60344"
FT /ligand_label="1"
FT /ligand_part="Fe"
FT /ligand_part_id="ChEBI:CHEBI:18248"
FT /note="axial binding residue"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_00633"
FT BINDING 187
FT /ligand="heme b"
FT /ligand_id="ChEBI:CHEBI:60344"
FT /ligand_label="2"
FT /ligand_part="Fe"
FT /ligand_part_id="ChEBI:CHEBI:18248"
FT /note="axial binding residue"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_00633"
FT BINDING 202
FT /ligand="heme b"
FT /ligand_id="ChEBI:CHEBI:60344"
FT /ligand_label="1"
FT /ligand_part="Fe"
FT /ligand_part_id="ChEBI:CHEBI:18248"
FT /note="axial binding residue"
FT /evidence="ECO:0000256|HAMAP-Rule:MF_00633"
SQ SEQUENCE 215 AA; 24273 MW; 272ECF1C60C4A963 CRC64;
MANVYDWFEE RLEIQAIAED VTSKYVPPHV NIFYCLGGIT LVCFLIQFAT GFAMTFYYKP
TVAEAYSSVQ YIMNEVNFGW LIRSIHRWSA SMMVLMMILH VFRVYLTGGF KKPRELTWVS
GVILAVITVS FGVTGYSLPW DQVGYWAVKI VSGVPEAIPV VGVLISDLLR GGSSVGQATL
TRYYSAHTFV LPWLIAVFML FHFLMIRKQG ISGPL
//
