CYB6_HORVU
ID CYB6_HORVU Reviewed; 215 AA.
AC P60161; A1E9M0; P12362; Q32438;
DT 28-NOV-2003, integrated into UniProtKB/Swiss-Prot.
DT 28-NOV-2003, sequence version 1.
DT 03-AUG-2022, entry version 99.
DE RecName: Full=Cytochrome b6 {ECO:0000255|HAMAP-Rule:MF_00633};
GN Name=petB {ECO:0000255|HAMAP-Rule:MF_00633};
OS Hordeum vulgare (Barley).
OG Plastid; Chloroplast.
OC Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC Spermatophyta; Magnoliopsida; Liliopsida; Poales; Poaceae; BOP clade;
OC Pooideae; Triticodae; Triticeae; Hordeinae; Hordeum.
OX NCBI_TaxID=4513;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA] (ISOFORMS 1 AND 2).
RC STRAIN=cv. Sabarlis;
RX PubMed=2654887; DOI=10.1093/nar/17.7.2859;
RA Andreeva A.V., Buryakova A.A., Reverdatto S.V., Chakhmakhcheva O.G.,
RA Efimov V.A.;
RT "Nucleotide sequence of the 5.2 kbp barley chloroplast DNA fragment,
RT containing psbB-psbH-petB-petD gene cluster.";
RL Nucleic Acids Res. 17:2859-2860(1989).
RN [2]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA] (ISOFORM 1).
RC STRAIN=cv. Sabarlis;
RX PubMed=1804121;
RA Efimov V.A., Andreeva A.V., Reverdatto S.V., Chakhmakhcheva O.G.;
RT "Photosystem II of rye. Nucleotide sequence of the psbB, psbC, psbE, psbF,
RT psbH genes of rye and chloroplast DNA regions adjacent to them.";
RL Bioorg. Khim. 17:1369-1385(1991).
RN [3]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=cv. Morex;
RX PubMed=17534593; DOI=10.1007/s00122-007-0567-4;
RA Saski C., Lee S.-B., Fjellheim S., Guda C., Jansen R.K., Luo H.,
RA Tomkins J., Rognli O.A., Daniell H., Clarke J.L.;
RT "Complete chloroplast genome sequences of Hordeum vulgare, Sorghum bicolor
RT and Agrostis stolonifera, and comparative analyses with other grass
RT genomes.";
RL Theor. Appl. Genet. 115:571-590(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; 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 -!- ALTERNATIVE PRODUCTS:
CC Event=Alternative splicing; Named isoforms=2;
CC Name=1;
CC IsoId=P60161-1; Sequence=Displayed;
CC Name=2;
CC IsoId=P60161-2; Sequence=VSP_007118;
CC -!- RNA EDITING: Modified_positions=204 {ECO:0000250};
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 -!- MISCELLANEOUS: [Isoform 2]: Unspliced isoform. {ECO:0000305}.
CC -!- SIMILARITY: Belongs to the cytochrome b family. PetB subfamily.
CC {ECO:0000255|HAMAP-Rule:MF_00633}.
CC -!- SEQUENCE CAUTION:
CC Sequence=ABK79441.1; Type=Erroneous initiation; Evidence={ECO:0000305};
CC -!- SEQUENCE CAUTION: [Isoform 2]:
CC Sequence=ABK79441.1; Type=Miscellaneous discrepancy; Note=wrong initiation.; Evidence={ECO:0000305};
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DR EMBL; X14107; CAA32266.1; ALT_SEQ; Genomic_DNA.
DR EMBL; X14107; CAA32267.1; ALT_SEQ; Genomic_DNA.
DR EMBL; EF115541; ABK79441.1; ALT_INIT; Genomic_DNA.
DR PIR; S04149; S04149.
DR PIR; S09186; S09186.
DR AlphaFoldDB; P60161; -.
DR SMR; P60161; -.
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 Alternative splicing; Chloroplast; Electron transport; Heme; Iron;
KW Membrane; Metal-binding; Photosynthesis; Plastid; RNA editing; Thylakoid;
KW Transmembrane; Transmembrane helix; Transport.
FT CHAIN 1..215
FT /note="Cytochrome b6"
FT /id="PRO_0000061797"
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"
FT VAR_SEQ 1..2
FT /note="MS -> MKFSYTALRGGRGLVTYLN (in isoform 2)"
FT /evidence="ECO:0000305"
FT /id="VSP_007118"
SQ SEQUENCE 215 AA; 24183 MW; C2E389FB10B51E6B CRC64;
MSKVYDWFEE RLEIQAIADD ITSKYVPPHV NIFYCLGGIT LTCFLVQVAT GFAMTFYYRP
TVTEAFSSVQ YIMTEANFGW LIRSVHRWSA SMMVLMMILH VFRVYLTGGF KKPRELTWVT
GVVLAVLTAS FGVTGYSLPW DQIGYWAVKI VTGVPDAIPV IGSPLVELLR GSASVGQSTL
TRFYSLHTFV LPLLTAVFML MHFLMIRKQG ISGPL
