CYB6_GRATL
ID CYB6_GRATL Reviewed; 215 AA.
AC Q6B903;
DT 15-MAR-2005, integrated into UniProtKB/Swiss-Prot.
DT 13-SEP-2004, sequence version 1.
DT 03-AUG-2022, entry version 83.
DE RecName: Full=Cytochrome b6 {ECO:0000255|HAMAP-Rule:MF_00633};
GN Name=petB {ECO:0000255|HAMAP-Rule:MF_00633}; OrderedLocusNames=Grc000051;
OS Gracilaria tenuistipitata var. liui (Red alga).
OG Plastid; Chloroplast.
OC Eukaryota; Rhodophyta; Florideophyceae; Rhodymeniophycidae; Gracilariales;
OC Gracilariaceae; Agarophyton; Agarophyton tenuistipitatum.
OX NCBI_TaxID=285951;
RN [1]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RX PubMed=15638458; DOI=10.1007/s00239-004-2638-3;
RA Hagopian J.C., Reis M., Kitajima J.P., Bhattacharya D., de Oliveira M.C.;
RT "Comparative analysis of the complete plastid genome sequence of the red
RT alga Gracilaria tenuistipitata var. liui provides insights into the
RT evolution of rhodoplasts and their relationship to other plastids.";
RL J. Mol. Evol. 59:464-477(2004).
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; AY673996; AAT79632.1; -; Genomic_DNA.
DR RefSeq; YP_063557.1; NC_006137.1.
DR AlphaFoldDB; Q6B903; -.
DR SMR; Q6B903; -.
DR GeneID; 2944153; -.
DR GO; GO:0009535; C:chloroplast thylakoid membrane; IEA:UniProtKB-SubCell.
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; 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 3: Inferred from homology;
KW Chloroplast; Electron transport; Heme; Iron; Membrane; Metal-binding;
KW Photosynthesis; Plastid; Thylakoid; Transmembrane; Transmembrane helix;
KW Transport.
FT CHAIN 1..215
FT /note="Cytochrome b6"
FT /id="PRO_0000061794"
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; 24182 MW; 396A01997FD8E3CD CRC64;
MGKVYDWFEE RLEIQAIADD ITSKYVPPHV NIFYCIGGIV FTSFLIQVAS GFAMTFYYRP
TVAEAFSSVE YIMTDVNFGW LIRSIHRWSA SMMVLMLILH MFRVYLTGGF KKPRELTWVT
GVILAVLTVS FGVTGYSLPW DQIGYWAVKI VTGVPEAIPV VGGSIVELLR GGVSVGQSTL
TRFYSLHTFV LPLLTAVFML MHFLMIRKQG ISGPL
