AC MF_00458; DC Protein; auto TR HAMAP; MF_00458; -; 1; level=0 XX Names: PSI_PsaA XX ID PSAA case not DE RecName: Full=Photosystem I P700 chlorophyll a apoprotein A1; DE EC=1.97.1.12; DE AltName: Full=PsaA; else case DE RecName: Full=Photosystem I P700 chlorophyll a apoprotein A1; DE EC=1.97.1.12; DE AltName: Full=PSI-A; DE AltName: Full=PsaA; end case GN Name=psaA; XX case or and not 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. else case and 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. end case 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; case and not CC -!- COFACTOR: CC Note=PSI electron transfer chain: 5 chlorophyll a, 1 chlorophyll a', 2 CC phylloquinones and 3 4Fe-4S clusters. PSI core antenna: 90 chlorophyll CC a, 22 carotenoids, 3 phospholipids and 1 galactolipid. P700 is a CC chlorophyll a/chlorophyll a' dimer, A0 is one or more chlorophyll a, A1 CC is one or both phylloquinones and FX is a shared 4Fe-4S iron-sulfur CC center.; 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 CC cyanobacterial PSI reaction center is composed of one copy each of CC PsaA,B,C,D,E,F,I,J,K,L,M and X, and forms trimeric complexes. else case CC -!- COFACTOR: CC Note=PSI electron transfer chain: 5 divinyl chlorophyll a, 1 divinyl CC chlorophyll a', 2 phylloquinones and 3 4Fe-4S clusters. PSI core CC antenna: 90 divinyl chlorophyll a, 22 carotenoids, 3 phospholipids and CC 1 galactolipid. P700 is a divinyl chlorophyll a/divinyl chlorophyll a' CC dimer, A0 is one or more divinyl chlorophyll a, A1 is one or both CC phylloquinones and FX is a shared 4Fe-4S iron-sulfur center.; CC -!- SUBUNIT: The PsaA/B heterodimer binds the P700 divinyl chlorophyll CC special pair and subsequent electron acceptors. PSI consists of a core CC antenna complex that captures photons, and an electron transfer chain CC that converts photonic excitation into a charge separation. The CC cyanobacterial PSI reaction center is composed of one copy each of CC PsaA,B,C,D,E,F,I,J,K,L,M and X, and forms trimeric complexes. else case 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.; 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. end case case CC -!- SUBCELLULAR LOCATION: Plastid, chloroplast thylakoid membrane; Multi- CC pass membrane protein. else case CC -!- SUBCELLULAR LOCATION: Cell inner membrane; Multi-pass membrane protein. else CC -!- SUBCELLULAR LOCATION: Cellular thylakoid membrane; Multi-pass membrane CC protein. end case CC -!- SIMILARITY: Belongs to the PsaA/PsaB family. XX DR Pfam; PF00223; PsaA_PsaB; 1; trigger=no DR PIRSF; PIRSF002905; PSI_A; 1; trigger=no DR PRINTS; PR00257; PHOTSYSPSAAB; 1; trigger=no DR NCBIfam; TIGR01335; PsaA; 1; trigger=no DR PROSITE; PS00419; PHOTOSYSTEM_I_PSAAB; 1; trigger=no XX KW Transport KW Electron transport KW Photosynthesis case KW Cell membrane KW Cell inner membrane else KW Thylakoid end case KW Photosystem I KW Chromophore KW Chlorophyll KW Oxidoreductase KW Metal-binding KW Iron KW Magnesium KW Iron-sulfur KW 4Fe-4S KW Membrane KW Transmembrane KW Transmembrane helix XX GO GO:0009055; F:electron transfer activity GO GO:0000287; F:magnesium ion binding GO GO:0015979; P:photosynthesis case GO GO:0009535; C:chloroplast thylakoid membrane else case GO GO:0005886; C:plasma membrane else GO GO:0042651; C:thylakoid membrane end case XX FT From: PSAA_THEVB (P0A405) FT TRANSMEM 72..95 FT /note="Helical; Name=I" FT TRANSMEM 158..181 FT /note="Helical; Name=II" FT TRANSMEM 197..221 FT /note="Helical; Name=III" FT TRANSMEM 297..315 FT /note="Helical; Name=IV" FT TRANSMEM 352..375 FT /note="Helical; Name=V" FT TRANSMEM 391..417 FT /note="Helical; Name=VI" FT TRANSMEM 439..461 FT /note="Helical; Name=VII" FT TRANSMEM 536..554 FT /note="Helical; Name=VIII" FT TRANSMEM 594..615 FT /note="Helical; Name=IX" FT TRANSMEM 669..691 FT /note="Helical; Name=X" FT TRANSMEM 729..749 FT /note="Helical; Name=XI" FT BINDING 578 FT /ligand="[4Fe-4S] cluster" FT /ligand_id="ChEBI:CHEBI:49883" FT /ligand_note="ligand shared between dimeric partners" FT Condition: C FT BINDING 587 FT /ligand="[4Fe-4S] cluster" FT /ligand_id="ChEBI:CHEBI:49883" FT /ligand_note="ligand shared between dimeric partners" FT Condition: C case not FT BINDING 680 FT /ligand="chlorophyll a'" FT /ligand_id="ChEBI:CHEBI:189419" FT /ligand_label="A1" FT /ligand_part="Mg" FT /ligand_part_id="ChEBI:CHEBI:25107" FT /note="axial binding residue" FT Condition: H FT BINDING 688 FT /ligand="chlorophyll a" FT /ligand_id="ChEBI:CHEBI:58416" FT /ligand_label="A3" FT /ligand_part="Mg" FT /ligand_part_id="ChEBI:CHEBI:25107" FT /note="axial binding residue" FT Condition: M FT BINDING 696 FT /ligand="chlorophyll a" FT /ligand_id="ChEBI:CHEBI:58416" FT /ligand_label="A3" FT Condition: Y end case case FT BINDING 680 FT /ligand="divinylchlorophyll a'" FT /ligand_id="ChEBI:CHEBI:189420" FT /ligand_label="A1" FT /ligand_part="Mg" FT /ligand_part_id="ChEBI:CHEBI:25107" FT /note="axial binding residue" FT Condition: H FT BINDING 688 FT /ligand="divinyl chlorophyll a" FT /ligand_id="ChEBI:CHEBI:73095" FT /ligand_label="A3" FT /ligand_part="Mg" FT /ligand_part_id="ChEBI:CHEBI:25107" FT /note="axial binding residue" FT Condition: M FT BINDING 696 FT /ligand="divinyl chlorophyll a" FT /ligand_id="ChEBI:CHEBI:73095" FT /ligand_label="A3" FT Condition: Y end case FT BINDING 697 FT /ligand="phylloquinone" FT /ligand_id="ChEBI:CHEBI:18067" FT /ligand_label="A" FT Condition: W XX Size: 678-783; Related: None; Template: P12154; P06511; P0A405; P0A406; Scope: Bacteria; Cyanobacteriota Plastid Fusion: Nter: None Cter: None Duplicate: None Plasmid: None Comments: None XX # Revision 1.65 2023/06/01 //