CYB6_CUSRE
ID CYB6_CUSRE Reviewed; 215 AA.
AC A7M993;
DT 23-OCT-2007, integrated into UniProtKB/Swiss-Prot.
DT 23-OCT-2007, sequence version 2.
DT 03-AUG-2022, entry version 64.
DE RecName: Full=Cytochrome b6;
GN Name=petB;
OS Cuscuta reflexa (Southern Asian dodder).
OG Plastid.
OC Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae;
OC asterids; lamiids; Solanales; Convolvulaceae; Cuscuteae; Cuscuta;
OC Cuscuta subgen. Monogynella.
OX NCBI_TaxID=4129;
RN [1]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA], AND RNA EDITING.
RX PubMed=17714582; DOI=10.1186/1471-2229-7-45;
RA Funk H.T., Berg S., Krupinska K., Maier U.-G., Krause K.;
RT "Complete DNA sequences of the plastid genomes of two parasitic flowering
RT plant species, Cuscuta reflexa and Cuscuta gronovii.";
RL BMC Plant Biol. 7:45-45(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:0000250}.
CC -!- COFACTOR:
CC Name=heme; Xref=ChEBI:CHEBI:30413; Evidence={ECO:0000250};
CC Note=Binds 2 heme groups. One heme group is bound covalently by a
CC single cysteine link, the other one non-covalently. {ECO:0000250};
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 (By similarity). {ECO:0000250}.
CC -!- SUBCELLULAR LOCATION: Plastid thylakoid membrane {ECO:0000305}; Multi-
CC pass membrane protein {ECO:0000305}.
CC -!- RNA EDITING: Modified_positions=140 {ECO:0000269|PubMed:17714582}, 204
CC {ECO:0000269|PubMed:17714582};
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:0000250}.
CC -!- SIMILARITY: Belongs to the cytochrome b family. PetB subfamily.
CC {ECO:0000305}.
CC -!- CAUTION: Young tissue from this organism is photosynthetic and contains
CC some thylakoids, although the photosynthetic activity does not exceed
CC the light compensation point. {ECO:0000305}.
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DR EMBL; AM711640; CAM98421.1; ALT_SEQ; Genomic_DNA.
DR RefSeq; YP_001430134.1; NC_009766.1.
DR AlphaFoldDB; A7M993; -.
DR SMR; A7M993; -.
DR PRIDE; A7M993; -.
DR GeneID; 5536694; -.
DR GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
DR GO; GO:0055035; C:plastid 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 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 2: Evidence at transcript level;
KW Electron transport; Heme; Iron; Membrane; Metal-binding; Photosynthesis;
KW Plastid; RNA editing; Thylakoid; Transmembrane; Transmembrane helix;
KW Transport.
FT CHAIN 1..215
FT /note="Cytochrome b6"
FT /id="PRO_0000308481"
FT TRANSMEM 32..52
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TRANSMEM 90..110
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TRANSMEM 116..136
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TRANSMEM 186..206
FT /note="Helical"
FT /evidence="ECO:0000255"
FT BINDING 35
FT /ligand="heme"
FT /ligand_id="ChEBI:CHEBI:30413"
FT /ligand_label="1"
FT /note="covalent"
FT /evidence="ECO:0000250"
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:0000250"
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:0000250"
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:0000250"
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:0000250"
SQ SEQUENCE 215 AA; 24161 MW; A1F25C669E5408B2 CRC64;
MSKVYDWLEE RLEIQAIADD ITSKYVPPHV NIFYCLGGIT LTCFLVQVAT GFAMTFYYRP
TVTEAFASVK YIMTEANFGW LIRSVHRWSA SMMVLMMILH VFRVYLTGGF KKPRELTWVT
GVVLAVLTAS FGVTGYSLPW DQIGYWAVKI VTGVPEAIPL IGSPLVELLR GSASVGQSTL
TRFYSLHTFV LPLITAVFML MHFLMIRKQG ISGPL
