ID CYB6_PHATC Reviewed; 215 AA.
AC A0T0B8;
DT 06-FEB-2007, integrated into UniProtKB/Swiss-Prot.
DT 09-JAN-2007, sequence version 1.
DT 27-MAR-2024, entry version 72.
DE RecName: Full=Cytochrome b6 {ECO:0000255|HAMAP-Rule:MF_00633};
GN Name=petB {ECO:0000255|HAMAP-Rule:MF_00633};
OS Phaeodactylum tricornutum (strain CCAP 1055/1).
OG Plastid; Chloroplast.
OC Eukaryota; Sar; Stramenopiles; Ochrophyta; Bacillariophyta;
OC Bacillariophyceae; Bacillariophycidae; Naviculales; Phaeodactylaceae;
OC Phaeodactylum.
OX NCBI_TaxID=556484;
RN [1]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=CCAP 1055/1;
RX PubMed=17252281; DOI=10.1007/s00438-006-0199-4;
RA Oudot-Le Secq M.-P., Grimwood J., Shapiro H., Armbrust E.V., Bowler C.,
RA Green B.R.;
RT "Chloroplast genomes of the diatoms Phaeodactylum tricornutum and
RT Thalassiosira pseudonana: comparison with other plastid genomes of the red
RT lineage.";
RL Mol. Genet. Genomics 277:427-439(2007).
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 b; Xref=ChEBI:CHEBI:60344;
CC Evidence={ECO:0000255|HAMAP-Rule:MF_00633};
CC Note=Binds 2 heme b groups non-covalently with two histidine residues
CC as axial ligands. {ECO:0000255|HAMAP-Rule:MF_00633};
CC -!- COFACTOR:
CC Name=heme c; Xref=ChEBI:CHEBI:61717;
CC Evidence={ECO:0000255|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: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 and
CC the Rieske protein, while the 4 small subunits are PetG, PetL, PetM and
CC PetN. The complex functions as a dimer. {ECO:0000255|HAMAP-
CC 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 absorbs at
CC about 566 nm, and heme 2 (or BL or b562) is low-potential and absorbs
CC at about 562 nm. {ECO:0000255|HAMAP-Rule:MF_00633}.
CC -!- SIMILARITY: Belongs to the cytochrome b family. PetB subfamily.
CC {ECO:0000255|HAMAP-Rule:MF_00633}.
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DR EMBL; EF067920; ABK20616.1; -; Genomic_DNA.
DR RefSeq; YP_874393.1; NC_008588.1.
DR AlphaFoldDB; A0T0B8; -.
DR SMR; A0T0B8; -.
DR STRING; 556484.A0T0B8; -.
DR GeneID; 4524678; -.
DR InParanoid; A0T0B8; -.
DR Proteomes; UP000000759; Chloroplast.
DR GO; GO:0009535; C:chloroplast 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 Chloroplast; Electron transport; Heme; Iron; Membrane; Metal-binding;
KW Photosynthesis; Plastid; Reference proteome; Thylakoid; Transmembrane;
KW Transmembrane helix; Transport.
FT CHAIN 1..215
FT /note="Cytochrome b6"
FT /id="PRO_0000275343"
FT TRANSMEM 32..52
FT /note="Helical"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00633"
FT TRANSMEM 90..110
FT /note="Helical"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00633"
FT TRANSMEM 116..136
FT /note="Helical"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00633"
FT TRANSMEM 186..206
FT /note="Helical"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00633"
FT BINDING 35
FT /ligand="heme c"
FT /ligand_id="ChEBI:CHEBI:61717"
FT /note="covalent"
FT /evidence="ECO:0000255|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:0000255|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:0000255|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:0000255|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:0000255|HAMAP-Rule:MF_00633"
SQ SEQUENCE 215 AA; 23992 MW; 38FDA1211EE35FC1 CRC64;
MNKVYDWFEE RLEVQAIADD ISSKYVPPHV NIFYCFGGLV LTCFLIQVAT GFAMTFYYRP
SVVDAFASVE YIMTSVNFGW LIRSIHRWSA SMMVLMMVLH VFRVYLTGGF KKPRELTWVT
GVTLSVVTVS FGVTGYSLPW DQVGFWACKI VTGVPAAVPI VGEPLVLILR GGESVGQSTL
TRFYSAHTFV LPLAAAVLML THFLMIRKQG ISGPL
//
