PSAB_STAPU
ID PSAB_STAPU Reviewed; 734 AA.
AC Q32RS4;
DT 06-FEB-2007, integrated into UniProtKB/Swiss-Prot.
DT 06-DEC-2005, sequence version 1.
DT 03-AUG-2022, entry version 65.
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 Staurastrum punctulatum (Green alga) (Cosmoastrum punctulatum).
OG Plastid; Chloroplast.
OC Eukaryota; Viridiplantae; Streptophyta; Zygnemophyceae; Zygnematophycidae;
OC Desmidiales; Desmidiaceae; Staurastrum.
OX NCBI_TaxID=102822;
RN [1]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RX PubMed=16236178; DOI=10.1186/1741-7007-3-22;
RA Turmel M., Otis C., Lemieux C.;
RT "The complete chloroplast DNA sequences of the charophycean green algae
RT Staurastrum and Zygnema reveal that the chloroplast genome underwent
RT extensive changes during the evolution of the Zygnematales.";
RL BMC Biol. 3:22-22(2005).
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; AY958085; AAX45716.1; -; Genomic_DNA.
DR RefSeq; YP_636452.1; NC_008116.1.
DR AlphaFoldDB; Q32RS4; -.
DR SMR; Q32RS4; -.
DR GeneID; 4108676; -.
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_0000277136"
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; 81863 MW; 9F97890279013408 CRC64;
MASRFPKFSQ GLAQDPTTRR IWFGIATAHD FESHDDMTEE KLYQKIFASH FGQLAIIFLW
TSGNLFHVAW QGNFEAWSQD PLHIRPIAHA IWDPHFGQPA VEAYTRGGAS GPVNISYSGV
YQWWYTIGLR TNQDLYTGSL FLLGLAAVAL VAGWLHLQPK WKPSVSWFKN AESRLNHHLS
GLFGVSSLAW TGHLIHVAIP EARGQHVRWD NFLSVAPHPQ GLAPFFAGQW GVYAQDPDSS
SHLFGTAQGS GTAILTFLGG FHPQTQSLWL TDIAHHHLAI AVLFIVAGHM YRTNFGIGHS
MKEILEAHVP PGGGLGRGHQ GLYDTVNNSL HFQLGLALAC LGVITSLVAQ HIYSLPPYAF
LAQDFTTQAA LYTHHQYIAG FIMTGAFAHG AIFFIRDYNP EQNKGNVLAR MLEHKEAIIS
HLSWASLFLG FHTLGLYVHN DVMLAFGTPE KQILIEPVFA QWIQSSHGKT LYGFDVLLSS
SSSIALNAGK SLWLPGWLDA INNNSNSLFL TIGPGDFLVH HAIALGLHTT TLILVKGALD
ARGSKLMPDK KEFGFSFPCD GPGRGGTCDI SAYDAFYLAV FWMLNTIGWV TFYWHWKHLG
LWQGNVAQFN ESSTYLMGWL RDYLWLNSSQ LINGYNPFGM NSLSVWAWMF LFGHLVWATG
FMFLISWRGY WQELIETLAW AHERTPLANL VRWKDKPVAL SIVQARLVGL AHFSVGYIFT
YAAFLIASTS GKFG
