PSAB_THAPS
ID PSAB_THAPS Reviewed; 733 AA.
AC A0T0M9;
DT 06-FEB-2007, integrated into UniProtKB/Swiss-Prot.
DT 09-JAN-2007, sequence version 1.
DT 03-AUG-2022, entry version 67.
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 Thalassiosira pseudonana (Marine diatom) (Cyclotella nana).
OG Plastid; Chloroplast.
OC Eukaryota; Sar; Stramenopiles; Ochrophyta; Bacillariophyta;
OC Coscinodiscophyceae; Thalassiosirophycidae; Thalassiosirales;
OC Thalassiosiraceae; Thalassiosira.
OX NCBI_TaxID=35128;
RN [1]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=CCMP1335 / NEPCC58 / CCAP 1085/12;
RX PubMed=17252281; DOI=10.1007/s00438-006-0199-4;
RA Oudot-Le Secq M.-P., Grimwood J., Shapiro H., Armbrust E.V., Bowler C.,
RA Green B.R.;
RT "Chloroplast genomes of the diatoms Phaeodactylum tricornutum and
RT Thalassiosira pseudonana: comparison with other plastid genomes of the red
RT lineage.";
RL Mol. Genet. Genomics 277:427-439(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; EF067921; ABK20714.1; -; Genomic_DNA.
DR RefSeq; YP_874491.1; NC_008589.1.
DR AlphaFoldDB; A0T0M9; -.
DR SMR; A0T0M9; -.
DR STRING; 35128.Thapsdraft1611; -.
DR PRIDE; A0T0M9; -.
DR GeneID; 4524814; -.
DR eggNOG; ENOG502QRYE; Eukaryota.
DR InParanoid; A0T0M9; -.
DR OMA; FEQWVAD; -.
DR Proteomes; UP000001449; 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_0000277143"
FT TRANSMEM 46..69
FT /note="Helical; Name=I"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 134..157
FT /note="Helical; Name=II"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 174..198
FT /note="Helical; Name=III"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 272..290
FT /note="Helical; Name=IV"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 329..352
FT /note="Helical; Name=V"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 368..394
FT /note="Helical; Name=VI"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00482"
FT TRANSMEM 416..438
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; 82089 MW; F5C6FCBE674FB914 CRC64;
MATKFPKFSQ ALAQDPATRR IWYGIATAHD LEAHDGMTEE NLYQKIFASH FGHLAIIFLW
TSGNLFHVAW QGNFEKWVSN PLKTRPIAHS IWDPHFGESA LKAFSKGNTY PVNITFSGLY
QWWYTIGFRT NQELYKGSIG LLLLASVLLI AGWLHLQPKF RPSLSWFKNN ESRLNHHLSG
LLGFSSLAWT GHLVHVAIPA SRGVHVGWDN FLTTPPHPAG LTPFFTGNWT VYAENPDSAT
HVFNTSEGSG TAILTFLGGF HPQTQSLWLS DMAHHHLAIA VVFIVAGHMY RTNFGIGHNM
KEILDAHRPP GGRLGAGHVG LFETITNSLH MQLGLALACL GVATSLTAQH MYALTPYAYL
SKDFTTEAAL YTHHQYIAGF LMVGAFAHGA IFFVRDYDPE LNKNNVLARM LEHKEAIISH
LSWASLFLGF HTLGLYIHND TVVAFGQPEK QILFEPLFAE YIQAASGKAV YQFNVLLASS
TSPATAAGNQ VWLPGWLEAI NNPKTDLFLK IGPGDFLVHH AIALGLHVTA LILVKGALDA
RGSKLMPDKK DFGYSFPCDG PGRGGTCDIS AWDAFYLAMF WMLNTIGWVT FYWHWKHMTI
WGGNPGQFDE SSNYIMGWLR DYLWLNSSPL INGYNPFGMN NLSVWSWMFL FGHLIWATGF
MFLISWRGYW QELIETLVWA HERTPLANLI RWRDKPVALS IVQARLVGLV HFSVGYILTY
AAFVIASTSG KFA
