PSAB_SELUN
ID PSAB_SELUN Reviewed; 734 AA.
AC Q2WGC5;
DT 06-FEB-2007, integrated into UniProtKB/Swiss-Prot.
DT 10-JAN-2006, sequence version 1.
DT 03-AUG-2022, entry version 61.
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 Selaginella uncinata (Blue spike-moss) (Lycopodium uncinatum).
OG Plastid; Chloroplast.
OC Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC Lycopodiopsida; Selaginellales; Selaginellaceae; Selaginella.
OX NCBI_TaxID=307165;
RN [1]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RX PubMed=17297557; DOI=10.1007/s10265-006-0055-y;
RA Tsuji S., Ueda K., Nishiyama T., Hasebe M., Yoshikawa S., Konagaya A.,
RA Nishiuchi T., Yamaguchi K.;
RT "The chloroplast genome from a lycophyte (microphyllophyte), Selaginella
RT uncinata, has a unique inversion, transpositions and many gene losses.";
RL J. Plant Res. 120:281-290(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-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; AB197035; BAE00251.1; -; Genomic_DNA.
DR AlphaFoldDB; Q2WGC5; -.
DR SMR; Q2WGC5; -.
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_0000275973"
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; 80815 MW; DF499362DDCBF44A CRC64;
MALRSPKSSR GLSQDPTTRR IWFGIATAHD FESHDGMTEE RLYQNIFASH LGQLAIIFLW
TSGNLFHVAW QGNSEARIKD PLHVRPIAHA IWDPHFGQPA VEAFARGGGL GPVNIAYPGV
YQRWYTIGMR TDQDLYTGAF SLLIVSTLFL VAGWLHLEPK WAPSISWFKN AESRLNHHLS
GLFGVSSLAR AGHLVHVAIP ESRGGHVRWG NLLSASPHPQ GLGPLSAGQW GVYARDVDSS
SHLFNTSQGA GTAIPTFTGG FHPQTQSPWL TDIAHHHLAI AVVFIIAGHT YRTNFGIGHS
IGGALEAHIP PGGRLGRGHQ GLYDTINNSL HFQLGLALAS LGVVTSLVAQ HMYSLPAYAF
IAQDFTTQAA LYTHHQYIAG FIMTGAFAHG AIFLTRDYSP ERGRGNVLAR VLEHKEAIIS
HLSWASLFLG FHTLGLYVHN DVMLAFGTPE KQILIEPVFA QWIQSAHGKA SYGFDVLLSS
PNDPAFNAGR SIWLPGRLDA IDNNSNSLFL TIGPGDFPVH HAIASGLHTT TLILSKGALD
ARGSKLMPDK KEFGYGFPCD GPGRGGTCDI SAWDAFYPAV FWMLNTIGWV TLHWHWKHIT
LWQGNVAQLD ESSTYLMGWS RDYSWLNSSQ LINGYNPFGT NSLSVWAWMF SFGHLVWATG
FMFLIPRRGY WQELIETLAR AHERTPLANL VRWGDKPVAL SIVQARLVGL AHFSVGYIFT
YAAFPIPSTA GKFG