PSAB_OSTTA
ID PSAB_OSTTA Reviewed; 733 AA.
AC Q0P3K2;
DT 06-FEB-2007, integrated into UniProtKB/Swiss-Prot.
DT 19-SEP-2006, sequence version 1.
DT 03-AUG-2022, entry version 73.
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}; OrderedLocusNames=OtCpg00500;
OS Ostreococcus tauri.
OG Plastid; Chloroplast.
OC Eukaryota; Viridiplantae; Chlorophyta; Mamiellophyceae; Mamiellales;
OC Bathycoccaceae; Ostreococcus.
OX NCBI_TaxID=70448;
RN [1]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=OTTH0595;
RX PubMed=17251180; DOI=10.1093/molbev/msm012;
RA Robbens S., Derelle E., Ferraz C., Wuyts J., Moreau H., Van de Peer Y.;
RT "The complete chloroplast and mitochondrial DNA sequence of Ostreococcus
RT tauri: organelle genomes of the smallest eukaryote are examples of
RT compaction.";
RL Mol. Biol. Evol. 24:956-968(2007).
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/cytochrome c6-ferredoxin oxidoreductase,
CC converting photonic excitation into a charge separation, which
CC transfers an electron from the donor P700 chlorophyll pair to the
CC spectroscopically characterized acceptors A0, A1, FX, FA and FB in
CC turn. Oxidized P700 is reduced on the lumenal side of the thylakoid
CC membrane by plastocyanin or cytochrome c6. {ECO:0000255|HAMAP-
CC 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; CR954199; CAL36375.1; -; Genomic_DNA.
DR RefSeq; YP_717253.1; NC_008289.1.
DR AlphaFoldDB; Q0P3K2; -.
DR SMR; Q0P3K2; -.
DR STRING; 70448.Q0P3K2; -.
DR GeneID; 4238874; -.
DR KEGG; ota:OstapCp50; -.
DR eggNOG; ENOG502QRYE; Eukaryota.
DR InParanoid; Q0P3K2; -.
DR OrthoDB; 209831at2759; -.
DR Proteomes; UP000009170; 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: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; Reference proteome; Thylakoid;
KW Transmembrane; Transmembrane helix; Transport.
FT CHAIN 1..733
FT /note="Photosystem I P700 chlorophyll a apoprotein A2"
FT /id="PRO_0000277125"
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 516..534
FT /note="Helical; Name=VIII"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 574..595
FT /note="Helical; Name=IX"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 642..664
FT /note="Helical; Name=X"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 706..726
FT /note="Helical; Name=XI"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT BINDING 558
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 567
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 653
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 661
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 669
FT /ligand="chlorophyll a"
FT /ligand_id="ChEBI:CHEBI:58416"
FT /ligand_label="B3"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT BINDING 670
FT /ligand="phylloquinone"
FT /ligand_id="ChEBI:CHEBI:18067"
FT /ligand_label="B"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
SQ SEQUENCE 733 AA; 81346 MW; 14CC18A0AD191062 CRC64;
MATKFPKFSQ GLASDPTTRR IWFGIATAHD FETHDGMTEE KLYQKIFASH FGQLAIIFLW
TSGNLFHVAW QGNFEKWGED PLHVRPIAHT IWDPHFGQPA VEAFTRGGAS APVNIAYSGV
YQWWYTIGMR TNVDLYNGSL FLLFVAGLFL FAGWLHLQPT FAPAVSWFKN AESRLNHHLS
GLFGVSSLAW TGHLVHVAIP ASRGETVRWD NFLTTLPHPA GLAPFFTGQW AVYAQNPDTA
GHIFGTSEGA GTAILTFLGG FHPQTQSLWL TDMAHHHLAI AVVFIIAGHQ YRTNFGIGHS
MKEILEAHTA PSGRLGAGHT GLFDTVNNSL HFQLGLALAS VGVLCSLTAQ HMYSMPPYAF
LAQDFTTQAA LYSHHQYIAG FIMCGAFAHG AIFFIRDYDP EANKGNVLAR MLEHKEAIIS
HLSWVSLFLG FHTLGLYVHN DVMQAFGTPE KQILIEPVFA QWIQAAQGKA LYGFDILLSG
DNAATAAGNS IYLPGWLAGI NSSTNSLFLP IGPGDFLVHH AIALGLHTTT LILVKGALDA
RGSKLMPDKK DFGYSFPCDG PGRGGTCDIS AWDAFYLAVF WELNTVSWTV FYFHWKHLAL
WQGNSAQFDE SSTYIMGWLR DYLWLNSSQL INGYNPFGMN SLSVWAWMFL FGHLIYATGF
MFLISWRGYW QELIETLVWA HERTPLANFV KWNDKPVALS IVQARLVGLT HFAVGFVLTY
AAFVIASTSG KFG
