CYB6_MAIZE
ID CYB6_MAIZE Reviewed; 215 AA.
AC P05642; Q33298; Q36712;
DT 01-NOV-1988, integrated into UniProtKB/Swiss-Prot.
DT 28-NOV-2003, sequence version 2.
DT 03-AUG-2022, entry version 141.
DE RecName: Full=Cytochrome b6 {ECO:0000255|HAMAP-Rule:MF_00633};
GN Name=petB {ECO:0000255|HAMAP-Rule:MF_00633};
OS Zea mays (Maize).
OG Plastid; Chloroplast.
OC Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC Spermatophyta; Magnoliopsida; Liliopsida; Poales; Poaceae; PACMAD clade;
OC Panicoideae; Andropogonodae; Andropogoneae; Tripsacinae; Zea.
OX NCBI_TaxID=4577;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA] (ISOFORMS 1 AND 2).
RX PubMed=2835175; DOI=10.1007/bf00420729;
RA Rock C.D., Barkan A., Taylor W.C.;
RT "The maize plastid psbB-psbF-petB-petD gene cluster: spliced and unspliced
RT petB and petD RNAs encode alternative products.";
RL Curr. Genet. 12:69-77(1987).
RN [2]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA] (ISOFORM 1), AND RNA EDITING.
RC TISSUE=Seedling;
RX PubMed=8252066; DOI=10.1046/j.1365-313x.1993.04040621.x;
RA Freyer R., Hoch B., Neckermann K., Maier R.M., Koessel H.;
RT "RNA editing in maize chloroplasts is a processing step independent of
RT splicing and cleavage to monocistronic mRNAs.";
RL Plant J. 4:621-629(1993).
RN [3]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=cv. B73;
RX PubMed=7666415; DOI=10.1006/jmbi.1995.0460;
RA Maier R.M., Neckermann K., Igloi G.L., Koessel H.;
RT "Complete sequence of the maize chloroplast genome: gene content, hotspots
RT of divergence and fine tuning of genetic information by transcript
RT editing.";
RL J. Mol. Biol. 251:614-628(1995).
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=P05642-1; Sequence=Displayed;
CC Name=2;
CC IsoId=P05642-2; Sequence=VSP_007116;
CC -!- RNA EDITING: Modified_positions=204 {ECO:0000269|PubMed:8252066};
CC Note=Editing is independent of both splicing and processing of the
CC primary transcript.;
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}.
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DR EMBL; X05422; CAA28999.1; ALT_SEQ; Genomic_DNA.
DR EMBL; X05422; CAA29000.1; ALT_SEQ; Genomic_DNA.
DR EMBL; S67283; AAB29194.1; -; Genomic_DNA.
DR EMBL; S67282; AAB29194.1; JOINED; Genomic_DNA.
DR EMBL; X86563; CAA60315.1; ALT_SEQ; Genomic_DNA.
DR PIR; S08592; CBZM6R.
DR PIR; S58581; S58581.
DR RefSeq; NP_043053.1; NC_001666.2.
DR AlphaFoldDB; P05642; -.
DR SMR; P05642; -.
DR STRING; 4577.GRMZM2G463640_P01; -.
DR PaxDb; P05642; -.
DR GeneID; 845192; -.
DR KEGG; zma:845192; -.
DR MaizeGDB; 56334; -.
DR eggNOG; KOG4663; Eukaryota.
DR OrthoDB; 1125966at2759; -.
DR Proteomes; UP000007305; Chloroplast.
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 2: Evidence at transcript level;
KW Alternative splicing; Chloroplast; Electron transport; Heme; Iron;
KW Membrane; Metal-binding; Photosynthesis; Plastid; Reference proteome;
KW RNA editing; Thylakoid; Transmembrane; Transmembrane helix; Transport.
FT CHAIN 1..215
FT /note="Cytochrome b6"
FT /id="PRO_0000061801"
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 -> MKFSYTVLGGGVGLVTYLN (in isoform 2)"
FT /evidence="ECO:0000305"
FT /id="VSP_007116"
SQ SEQUENCE 215 AA; 24197 MW; C2E389FA11B51F6A CRC64;
MSKVYDWFEE RLEIQAIADD ITSKYVPPHV NIFYCLGGIT LTCFLVQVAT GFAMTFYYRP
TVTEAFSSVQ YIMTEANFGW LIRSVHRWSA SMMVLMMILH VFRVYLTGGF KKPRELTWVT
GVVLAVLTAS FGVTGYSLPW DQIGYWAVKI VTGVPEAIPV IGSPLVELLR GSASVGQSTL
TRFYSLHTFV LPLLTAVFML MHFLMIRKQG ISGPL
