ID D7E556_NOSA0 Unreviewed; 215 AA.
AC D7E556;
DT 10-AUG-2010, integrated into UniProtKB/TrEMBL.
DT 10-AUG-2010, sequence version 1.
DT 27-MAR-2024, entry version 75.
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=Aazo_1703 {ECO:0000313|EMBL:ADI63853.1};
OS Nostoc azollae (strain 0708) (Anabaena azollae (strain 0708)).
OC Bacteria; Cyanobacteriota; Cyanophyceae; Nostocales; Nostocaceae;
OC Trichormus.
OX NCBI_TaxID=551115 {ECO:0000313|EMBL:ADI63853.1, ECO:0000313|Proteomes:UP000001511};
RN [1] {ECO:0000313|EMBL:ADI63853.1, ECO:0000313|Proteomes:UP000001511}
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=0708 {ECO:0000313|EMBL:ADI63853.1,
RC ECO:0000313|Proteomes:UP000001511};
RX PubMed=20628610; DOI=10.1371/journal.pone.0011486;
RA Ran L., Larsson J., Vigil-Stenman T., Nylander J.A., Ininbergs K.,
RA Zheng W.W., Lapidus A., Lowry S., Haselkorn R., Bergman B.;
RT "Genome erosion in a nitrogen-fixing vertically transmitted endosymbiotic
RT multicellular cyanobacterium.";
RL PLoS ONE 5:E11486-E11486(2010).
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; CP002059; ADI63853.1; -; Genomic_DNA.
DR RefSeq; WP_013190871.1; NC_014248.1.
DR AlphaFoldDB; D7E556; -.
DR STRING; 551115.Aazo_1703; -.
DR KEGG; naz:Aazo_1703; -.
DR eggNOG; COG1290; Bacteria.
DR HOGENOM; CLU_031114_0_2_3; -.
DR OrthoDB; 9804503at2; -.
DR Proteomes; UP000001511; 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:UP000001511};
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; 24260 MW; 6AA4C894A510D57C CRC64;
MANVYDWFEE RLDLEAIAED VTSKYVPPHV NIFYCLGGIT LVCFLIQFAT GFAMTFYYKP
TVAEAYSSVQ YIMNEVNFGW LIRSIHRWSA SMMVLMMILH VFRVYLTGGF KKPRELTWVS
GVILAVITVS FGVTGYSLPW DQVGYWAVKI VSGVPEAIPV VGVLISDLLR GGSSVGQATL
TRYYSAHTFV LPWLIAVFML FHFLMIRKQG ISGPL
//
