PSAB_CITSI
ID PSAB_CITSI Reviewed; 734 AA.
AC Q09MH9;
DT 06-FEB-2007, integrated into UniProtKB/Swiss-Prot.
DT 17-OCT-2006, sequence version 1.
DT 03-AUG-2022, entry version 64.
DE RecName: Full=Photosystem I P700 chlorophyll a apoprotein A2 {ECO:0000255|HAMAP-Rule:MF_00482};
DE EC=1.97.1.12 {ECO:0000255|HAMAP-Rule:MF_00482};
DE AltName: Full=PSI-B {ECO:0000255|HAMAP-Rule:MF_00482};
DE AltName: Full=PsaB {ECO:0000255|HAMAP-Rule:MF_00482};
GN Name=psaB {ECO:0000255|HAMAP-Rule:MF_00482};
OS Citrus sinensis (Sweet orange) (Citrus aurantium var. sinensis).
OG Plastid; Chloroplast.
OC Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae;
OC rosids; malvids; Sapindales; Rutaceae; Aurantioideae; Citrus.
OX NCBI_TaxID=2711;
RN [1]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=cv. Osbeck var. Ridge Pineapple;
RX PubMed=17010212; DOI=10.1186/1471-2229-6-21;
RA Bausher M.G., Singh N.D., Lee S.-B., Jansen R.K., Daniell H.;
RT "The complete chloroplast genome sequence of Citrus sinensis (L.) Osbeck
RT var 'Ridge Pineapple': organization and phylogenetic relationships to other
RT angiosperms.";
RL BMC Plant Biol. 6:21-21(2006).
CC -!- FUNCTION: PsaA and PsaB bind P700, the primary electron donor of
CC photosystem I (PSI), as well as the electron acceptors A0, A1 and FX.
CC PSI is a plastocyanin-ferredoxin oxidoreductase, converting photonic
CC excitation into a charge separation, which transfers an electron from
CC the donor P700 chlorophyll pair to the spectroscopically characterized
CC acceptors A0, A1, FX, FA and FB in turn. Oxidized P700 is reduced on
CC the lumenal side of the thylakoid membrane by plastocyanin.
CC {ECO:0000255|HAMAP-Rule:MF_00482}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=hnu + oxidized [2Fe-2S]-[ferredoxin] + reduced [plastocyanin]
CC = oxidized [plastocyanin] + reduced [2Fe-2S]-[ferredoxin];
CC Xref=Rhea:RHEA:30407, Rhea:RHEA-COMP:10000, Rhea:RHEA-COMP:10001,
CC Rhea:RHEA-COMP:10039, Rhea:RHEA-COMP:10040, ChEBI:CHEBI:29036,
CC ChEBI:CHEBI:30212, ChEBI:CHEBI:33737, ChEBI:CHEBI:33738,
CC ChEBI:CHEBI:49552; EC=1.97.1.12; Evidence={ECO:0000255|HAMAP-
CC Rule:MF_00482};
CC -!- COFACTOR:
CC Note=P700 is a chlorophyll a/chlorophyll a' dimer, A0 is one or more
CC chlorophyll a, A1 is one or both phylloquinones and FX is a shared 4Fe-
CC 4S iron-sulfur center. {ECO:0000255|HAMAP-Rule:MF_00482};
CC -!- SUBUNIT: The PsaA/B heterodimer binds the P700 chlorophyll special pair
CC and subsequent electron acceptors. PSI consists of a core antenna
CC complex that captures photons, and an electron transfer chain that
CC converts photonic excitation into a charge separation. The eukaryotic
CC PSI reaction center is composed of at least 11 subunits.
CC {ECO:0000255|HAMAP-Rule:MF_00482}.
CC -!- SUBCELLULAR LOCATION: Plastid, chloroplast thylakoid membrane; Multi-
CC pass membrane protein.
CC -!- SIMILARITY: Belongs to the PsaA/PsaB family. {ECO:0000255|HAMAP-
CC Rule:MF_00482}.
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DR EMBL; DQ864733; ABI49019.1; -; Genomic_DNA.
DR RefSeq; YP_740474.1; NC_008334.1.
DR AlphaFoldDB; Q09MH9; -.
DR SMR; Q09MH9; -.
DR GeneID; 4271130; -.
DR KEGG; cit:4271130; -.
DR OrthoDB; 209831at2759; -.
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:0009522; C:photosystem I; IEA:UniProtKB-KW.
DR GO; GO:0051539; F:4 iron, 4 sulfur cluster binding; IEA:UniProtKB-KW.
DR GO; GO:0016168; F:chlorophyll binding; IEA:UniProtKB-KW.
DR GO; GO:0009055; F:electron transfer activity; IEA:UniProtKB-UniRule.
DR GO; GO:0000287; F:magnesium ion binding; IEA:UniProtKB-UniRule.
DR GO; GO:0015979; P:photosynthesis; IEA:UniProtKB-UniRule.
DR Gene3D; 1.20.1130.10; -; 1.
DR HAMAP; MF_00482; PSI_PsaB; 1.
DR InterPro; IPR001280; PSI_PsaA/B.
DR InterPro; IPR020586; PSI_PsaA/B_CS.
DR InterPro; IPR036408; PSI_PsaA/B_sf.
DR InterPro; IPR006244; PSI_PsaB.
DR Pfam; PF00223; PsaA_PsaB; 1.
DR PIRSF; PIRSF002905; PSI_A; 1.
DR PRINTS; PR00257; PHOTSYSPSAAB.
DR SUPFAM; SSF81558; SSF81558; 1.
DR TIGRFAMs; TIGR01336; psaB; 1.
DR PROSITE; PS00419; PHOTOSYSTEM_I_PSAAB; 1.
PE 3: Inferred from homology;
KW 4Fe-4S; Chlorophyll; Chloroplast; Chromophore; Electron transport; Iron;
KW Iron-sulfur; Magnesium; Membrane; Metal-binding; Oxidoreductase;
KW Photosynthesis; Photosystem I; Plastid; Thylakoid; Transmembrane;
KW Transmembrane helix; Transport.
FT CHAIN 1..734
FT /note="Photosystem I P700 chlorophyll a apoprotein A2"
FT /id="PRO_0000277108"
FT TRANSMEM 46..69
FT /note="Helical; Name=I"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 135..158
FT /note="Helical; Name=II"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 175..199
FT /note="Helical; Name=III"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 273..291
FT /note="Helical; Name=IV"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 330..353
FT /note="Helical; Name=V"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 369..395
FT /note="Helical; Name=VI"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 417..439
FT /note="Helical; Name=VII"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 517..535
FT /note="Helical; Name=VIII"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 575..596
FT /note="Helical; Name=IX"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 643..665
FT /note="Helical; Name=X"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 707..727
FT /note="Helical; Name=XI"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT BINDING 559
FT /ligand="[4Fe-4S] cluster"
FT /ligand_id="ChEBI:CHEBI:49883"
FT /ligand_note="ligand shared between dimeric partners"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT BINDING 568
FT /ligand="[4Fe-4S] cluster"
FT /ligand_id="ChEBI:CHEBI:49883"
FT /ligand_note="ligand shared between dimeric partners"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT BINDING 654
FT /ligand="chlorophyll a"
FT /ligand_id="ChEBI:CHEBI:58416"
FT /ligand_label="B1"
FT /ligand_part="Mg"
FT /ligand_part_id="ChEBI:CHEBI:25107"
FT /note="axial binding residue"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT BINDING 662
FT /ligand="chlorophyll a"
FT /ligand_id="ChEBI:CHEBI:58416"
FT /ligand_label="B3"
FT /ligand_part="Mg"
FT /ligand_part_id="ChEBI:CHEBI:25107"
FT /note="axial binding residue"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT BINDING 670
FT /ligand="chlorophyll a"
FT /ligand_id="ChEBI:CHEBI:58416"
FT /ligand_label="B3"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT BINDING 671
FT /ligand="phylloquinone"
FT /ligand_id="ChEBI:CHEBI:18067"
FT /ligand_label="B"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
SQ SEQUENCE 734 AA; 82366 MW; 2BFC252C17216FEE CRC64;
MALRFPRFSQ GLAQDPTTRR IWFGIATAHD FESHDDITEE RLYQNIFASH FGQLAIIFLW
TSGNLFHVAW QGNFEAWVQD PLHVRPIAHA IWDPHFGQPA VEAFSRGGAL GPVNIAYSGV
YQWWYTIGLR TNEDLYTGAL FLLFLSAISL IAGWLHLQPK WKPSVSWFKN AESRLNHHLS
GLFGVSSLAW TGHLVHVAIP GSRGEYVRWN NFLDVLPHPQ GLGPLFTGQW NLYAQNPDSS
SHLFGTSQGS GTAILTLLGG FHPQTQSLWL TDIAHHHLAI AFIFLVAGHM YRTNFGIGHS
IKDLLEAHIP PGGRLGRGHK GLYDTINNSL HFQLGLALAS LGVITSLVAQ HMYSLPAYAF
IAQDFTTQAA LYTHHQYIAG FIMTGAFAHG AIFFIRDYNP EQNEDNVLAR MLDHKEAIIS
HLSWASLFLG FHTLGLYVHN DVMLAFGTPE KQILIEPIFA QWIQSAHGKT SYGFDVLLSS
TDGPAFNAGR SIWLPGWLSA VNENSNSLFL TIGPGDFLVH HAIALGLHTT TLILVKGALD
ARGSKLMPDK KDFGYSFPCD GPGRGGTCDI SAWDAFYLAV FWMLNTIGWV TFYWHWNHIT
LWQGNVSQFN ESSTYLMGWL RDYLWLNSSQ LINGYNPFGM NSLSVWAWMF LFGHLVWATG
FMFLISWRGY WQELIETLAW AHERTPLANL IRWRDKPVAL SIVQARLVGL AHFSVGYIFT
YAAFLIASTS GKFG
