CYB6_EUGGR
ID CYB6_EUGGR Reviewed; 215 AA.
AC P31480;
DT 01-JUL-1993, integrated into UniProtKB/Swiss-Prot.
DT 23-JAN-2007, sequence version 3.
DT 03-AUG-2022, entry version 113.
DE RecName: Full=Cytochrome b6 {ECO:0000255|HAMAP-Rule:MF_00633};
GN Name=petB {ECO:0000255|HAMAP-Rule:MF_00633};
OS Euglena gracilis.
OG Plastid; Chloroplast.
OC Eukaryota; Discoba; Euglenozoa; Euglenida; Spirocuta; Euglenophyceae;
OC Euglenales; Euglenaceae; Euglena.
OX NCBI_TaxID=3039;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC STRAIN=Z / UTEX 753;
RX PubMed=7923415; DOI=10.1007/bf00357173;
RA Hong L., Hallick R.B.;
RT "Gene structure and expression of a novel Euglena gracilis chloroplast
RT operon encoding cytochrome b6 and the beta and epsilon subunits of the
RT H(+)-ATP synthase complex.";
RL Curr. Genet. 25:270-281(1994).
RN [2]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=Z / UTEX 753;
RX PubMed=8346031; DOI=10.1093/nar/21.15.3537;
RA Hallick R.B., Hong L., Drager R.G., Favreau M.R., Monfort A., Orsat B.,
RA Spielmann A., Stutz E.;
RT "Complete sequence of Euglena gracilis chloroplast DNA.";
RL Nucleic Acids Res. 21:3537-3544(1993).
RN [3]
RP PROTEIN SEQUENCE OF 2-31, AND SUBCELLULAR LOCATION.
RX PubMed=12837550; DOI=10.1016/s0005-2728(03)00058-6;
RA Santillan Torres J.L., Atteia A., Claros M.G., Gonzalez-Halphen D.;
RT "Cytochrome f and subunit IV, two essential components of the
RT photosynthetic bf complex typically encoded in the chloroplast genome, are
RT nucleus-encoded in Euglena gracilis.";
RL Biochim. Biophys. Acta 1604:180-189(2003).
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. {ECO:0000255|HAMAP-
CC 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; X70810; CAA50129.1; -; Genomic_DNA.
DR PIR; S34548; S34548.
DR RefSeq; NP_041942.1; NC_001603.2.
DR AlphaFoldDB; P31480; -.
DR SMR; P31480; -.
DR GeneID; 807480; -.
DR GO; GO:0009535; C:chloroplast thylakoid membrane; IEA:UniProtKB-SubCell.
DR GO; GO:0009512; C:cytochrome b6f complex; IDA:UniProtKB.
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; NAS:UniProtKB.
DR GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR GO; GO:0009767; P:photosynthetic electron transport chain; NAS:UniProtKB.
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_sf.
DR InterPro; IPR016174; Di-haem_cyt_TM.
DR PANTHER; PTHR19271:SF20; PTHR19271:SF20; 1.
DR Pfam; PF00033; Cytochrome_B; 1.
DR SUPFAM; SSF81342; SSF81342; 1.
DR PROSITE; PS51002; CYTB_NTER; 1.
PE 1: Evidence at protein level;
KW Chloroplast; Direct protein sequencing; Electron transport; Heme; Iron;
KW Membrane; Metal-binding; Photosynthesis; Plastid; Thylakoid; Transmembrane;
KW Transmembrane helix; Transport.
FT INIT_MET 1
FT /note="Removed"
FT /evidence="ECO:0000269|PubMed:12837550"
FT CHAIN 2..215
FT /note="Cytochrome b6"
FT /id="PRO_0000061793"
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"
FT /ligand_id="ChEBI:CHEBI:30413"
FT /ligand_label="1"
FT /note="covalent"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00633"
FT BINDING 86
FT /ligand="heme"
FT /ligand_id="ChEBI:CHEBI:30413"
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"
FT /ligand_id="ChEBI:CHEBI:30413"
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"
FT /ligand_id="ChEBI:CHEBI:30413"
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"
FT /ligand_id="ChEBI:CHEBI:30413"
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; 24385 MW; 870C9E08CDFECCCB CRC64;
MSRVYDWFEE RLEIQAIADD VSSKYVPPHV NIFYCLGGIT FTCFIIQVAT GFAMTFYYRP
TVTEAFLSVK YIMNEVNFGW LIRSIHRWSA SMMVLMMILH VCRVYLTGGF KKPRELTWVT
GIILAILTVS FGVTGYSLPW DQVGYWAVKI VTGVPEAIPL IGNFIVELLR GSVSVGQSTL
TRFYSLHTFV LPLLTATFML GHFLMIRKQG ISGPL
