PSAB_HETTR
ID PSAB_HETTR Reviewed; 776 AA.
AC Q9XQV2;
DT 16-NOV-2001, integrated into UniProtKB/Swiss-Prot.
DT 01-NOV-1999, sequence version 1.
DT 03-AUG-2022, entry version 93.
DE RecName: Full=Photosystem I P700 chlorophyll a apoprotein A2;
DE EC=1.97.1.12;
DE AltName: Full=PSI-B;
DE AltName: Full=PsaB;
GN Name=psaB;
OS Heterocapsa triquetra (Dinoflagellate) (Glenodinium triquetrum).
OG Plastid; Chloroplast.
OC Eukaryota; Sar; Alveolata; Dinophyceae; Peridiniales; Heterocapsaceae;
OC Heterocapsa.
OX NCBI_TaxID=66468;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC STRAIN=CCMP449;
RX PubMed=10408440; DOI=10.1038/22099;
RA Zhang Z., Green B.R., Cavalier-Smith T.;
RT "Single gene circles in dinoflagellate chloroplast genomes.";
RL Nature 400:155-159(1999).
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 (By similarity).
CC {ECO:0000250}.
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;
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:0000250};
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 (By
CC similarity). {ECO:0000250}.
CC -!- SUBCELLULAR LOCATION: Plastid, chloroplast thylakoid membrane
CC {ECO:0000250}; Multi-pass membrane protein {ECO:0000250}.
CC -!- SIMILARITY: Belongs to the PsaA/PsaB family. {ECO:0000305}.
CC ---------------------------------------------------------------------------
CC Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms
CC Distributed under the Creative Commons Attribution (CC BY 4.0) License
CC ---------------------------------------------------------------------------
DR EMBL; AF130032; AAD44699.1; -; Genomic_DNA.
DR AlphaFoldDB; Q9XQV2; -.
DR SMR; Q9XQV2; -.
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:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR GO; GO:0016491; F:oxidoreductase activity; IEA:UniProtKB-KW.
DR GO; GO:0015979; P:photosynthesis; IEA:UniProtKB-KW.
DR Gene3D; 1.20.1130.10; -; 1.
DR InterPro; IPR001280; PSI_PsaA/B.
DR InterPro; IPR020586; PSI_PsaA/B_CS.
DR InterPro; IPR036408; PSI_PsaA/B_sf.
DR Pfam; PF00223; PsaA_PsaB; 2.
DR PIRSF; PIRSF002905; PSI_A; 1.
DR PRINTS; PR00257; PHOTSYSPSAAB.
DR SUPFAM; SSF81558; SSF81558; 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..776
FT /note="Photosystem I P700 chlorophyll a apoprotein A2"
FT /id="PRO_0000088617"
FT TRANSMEM 57..80
FT /note="Helical; Name=I"
FT /evidence="ECO:0000255"
FT TRANSMEM 150..173
FT /note="Helical; Name=II"
FT /evidence="ECO:0000255"
FT TRANSMEM 233..257
FT /note="Helical; Name=III"
FT /evidence="ECO:0000255"
FT TRANSMEM 334..352
FT /note="Helical; Name=IV"
FT /evidence="ECO:0000255"
FT TRANSMEM 382..405
FT /note="Helical; Name=V"
FT /evidence="ECO:0000255"
FT TRANSMEM 421..447
FT /note="Helical; Name=VI"
FT /evidence="ECO:0000255"
FT TRANSMEM 472..494
FT /note="Helical; Name=VII"
FT /evidence="ECO:0000255"
FT TRANSMEM 561..579
FT /note="Helical; Name=VIII"
FT /evidence="ECO:0000255"
FT TRANSMEM 619..640
FT /note="Helical; Name=IX"
FT /evidence="ECO:0000255"
FT TRANSMEM 687..709
FT /note="Helical; Name=X"
FT /evidence="ECO:0000255"
FT TRANSMEM 753..773
FT /note="Helical; Name=XI"
FT /evidence="ECO:0000255"
FT BINDING 603
FT /ligand="[4Fe-4S] cluster"
FT /ligand_id="ChEBI:CHEBI:49883"
FT /ligand_note="ligand shared between dimeric partners"
FT /evidence="ECO:0000250"
FT BINDING 612
FT /ligand="[4Fe-4S] cluster"
FT /ligand_id="ChEBI:CHEBI:49883"
FT /ligand_note="ligand shared between dimeric partners"
FT /evidence="ECO:0000250"
FT BINDING 698
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:0000250"
FT BINDING 706
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:0000250"
FT BINDING 714
FT /ligand="chlorophyll a"
FT /ligand_id="ChEBI:CHEBI:58416"
FT /ligand_label="B3"
FT /evidence="ECO:0000250"
FT BINDING 715
FT /ligand="phylloquinone"
FT /ligand_id="ChEBI:CHEBI:18067"
FT /ligand_label="B"
FT /evidence="ECO:0000250"
SQ SEQUENCE 776 AA; 86144 MW; F8640CA5F58C8913 CRC64;
MSLLDGRILG FTTHSDSFVS KRQSNGAATG RFFQVIGNIH DIESYYGIHG SQVNLQIFLS
HFGHLAIIFL WAAGNLFHIG WNGNYELWIL NPISTMPIAH GIWDPHFGAQ GEAVWGGVSA
TSGGSEAVVV SYSGIYNWLY AVGFTSVYEI YNFVIVLELL AVAALLLGKT HLIYNEELIQ
WLGTNKPYYR VGSDNEEVVS LYKKLALDMK VYPMFIWPFR IFLAAFDASG LRLNFHIGAL
IGFTSLAWAG HLIHVAIPAS RGIYHTISPV GDSTFAEPSL KALYPFYSGN WAYYAQDIDK
DNHIFGSTVG AGKAILTFLG GVKSDTASLY LTDIAHHHLA IGVLFIWAAH LYSSLYKGFG
HRIRDILVSA NSGMMIRSMN SYHLQLALAC AGVSVITSVV GQHIYSLAPY PYLAYDYVTT
VALYLHHSWI ASLLMMAAFA HAGIFLVRDY TVNPKTTTGE DIIGRVLAHK AAIISHLSWV
SLWLGFHTLG VYIHNDTVTA FGEPQNSILI EPIFAQIIQS ASGKTLYGTT LFSVVNPSSG
WVQSVNKSFG SLLLPIGPGD LLAHHAIALG LHVTVLILMK GALDARGSKL MPDKIHFGYG
FACDGPGRGG TCDISAWDSF YLAMFWMLNT NAWTIFYFHW KELTLWQNIT FQFDESSNYL
NGWFRDYLWF NSGSLIRGYD ALGANDLSVW AWIFLAAHLC WATGFMFLIS WRGYWQELID
IILYMHLKTP ILYDIWNAGV YTPVALSIVQ ARFIGLVHFA VGFIITYAAF IVGSTT
