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HAMAP rule MF_00458

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General rule information [?]

Accession MF_00458
Dates 1-JUN-2001 (Created)
1-JUN-2023 (Last updated, Version 65)
Name PSI_PsaA
Scope(s) Bacteria
Cyanobacteriota
Plastid
Template(s) P12154 (PSAA_CHLRE); P06511 (PSAA_SPIOL); P0A405 (PSAA_THEVB); P0A406 (PSAA_SYNEL); [ Recover all ]
Triggered by HAMAP; MF_00458 (Get profile general information and statistics)

Propagated annotation [?]

Identifier, protein and gene names [?]

Identifier PSAA
case not <OG:Chloroplast>
Protein name RecName: Full=Photosystem I P700 chlorophyll a apoprotein A1;
                 EC=1.97.1.12;
AltName: Full=PsaA;
else case <OG:Chloroplast>
Protein name RecName: Full=Photosystem I P700 chlorophyll a apoprotein A1;
                 EC=1.97.1.12;
AltName: Full=PSI-A;
AltName: Full=PsaA;
end case
Gene name Name=psaA;

Comments [?]

case <OC:Cyanobacteriota> or <OG:Chloroplast> and not <OC:Streptophyta>
FUNCTIONPsaA and PsaB bind P700, the primary electron donor of photosystem I (PSI), as well as the electron acceptors A0, A1 and FX. PSI is a plastocyanin/cytochrome c6-ferredoxin oxidoreductase, converting photonic excitation into a charge separation, which transfers an electron from the donor P700 chlorophyll pair to the spectroscopically characterized acceptors A0, A1, FX, FA and FB in turn. Oxidized P700 is reduced on the lumenal side of the thylakoid membrane by plastocyanin or cytochrome c6.
else case <OG:Chloroplast> and <OC:Streptophyta>
FUNCTIONPsaA and PsaB bind P700, the primary electron donor of photosystem I (PSI), as well as the electron acceptors A0, A1 and FX. PSI is a plastocyanin-ferredoxin oxidoreductase, converting photonic excitation into a charge separation, which transfers an electron from the donor P700 chlorophyll pair to the spectroscopically characterized acceptors A0, A1, FX, FA and FB in turn. Oxidized P700 is reduced on the lumenal side of the thylakoid membrane by plastocyanin.
end case
CATALYTIC ACTIVITY Reaction=hnu + oxidized [2Fe-2S]-[ferredoxin] + reduced [plastocyanin] = oxidized [plastocyanin] + reduced [2Fe-2S]-[ferredoxin]; Xref=Rhea:RHEA:30407, Rhea:RHEA-COMP:10000, Rhea:RHEA-COMP:10001, Rhea:RHEA-COMP:10039, Rhea:RHEA-COMP:10040, ChEBI:CHEBI:29036, ChEBI:CHEBI:30212, ChEBI:CHEBI:33737, ChEBI:CHEBI:33738, ChEBI:CHEBI:49552; EC=1.97.1.12;
case <OC:Cyanobacteriota> and not <OC:Prochlorococcus>
COFACTOR Note=PSI electron transfer chain: 5 chlorophyll a, 1 chlorophyll a', 2 phylloquinones and 3 4Fe-4S clusters. PSI core antenna: 90 chlorophyll a, 22 carotenoids, 3 phospholipids and 1 galactolipid. P700 is a chlorophyll a/chlorophyll a' dimer, A0 is one or more chlorophyll a, A1 is one or both phylloquinones and FX is a shared 4Fe-4S iron-sulfur center.;
SUBUNITThe PsaA/B heterodimer binds the P700 chlorophyll special pair and subsequent electron acceptors. PSI consists of a core antenna complex that captures photons, and an electron transfer chain that converts photonic excitation into a charge separation. The cyanobacterial PSI reaction center is composed of one copy each of PsaA,B,C,D,E,F,I,J,K,L,M and X, and forms trimeric complexes.
else case <OC:Prochlorococcus>
COFACTOR Note=PSI electron transfer chain: 5 divinyl chlorophyll a, 1 divinyl chlorophyll a', 2 phylloquinones and 3 4Fe-4S clusters. PSI core antenna: 90 divinyl chlorophyll a, 22 carotenoids, 3 phospholipids and 1 galactolipid. P700 is a divinyl chlorophyll a/divinyl chlorophyll a' dimer, A0 is one or more divinyl chlorophyll a, A1 is one or both phylloquinones and FX is a shared 4Fe-4S iron-sulfur center.;
SUBUNITThe PsaA/B heterodimer binds the P700 divinyl chlorophyll special pair and subsequent electron acceptors. PSI consists of a core antenna complex that captures photons, and an electron transfer chain that converts photonic excitation into a charge separation. The cyanobacterial PSI reaction center is composed of one copy each of PsaA,B,C,D,E,F,I,J,K,L,M and X, and forms trimeric complexes.
else case <OG:Chloroplast>
COFACTOR Note=P700 is a chlorophyll a/chlorophyll a' dimer, A0 is one or more chlorophyll a, A1 is one or both phylloquinones and FX is a shared 4Fe- 4S iron-sulfur center.;
SUBUNITThe PsaA/B heterodimer binds the P700 chlorophyll special pair and subsequent electron acceptors. PSI consists of a core antenna complex that captures photons, and an electron transfer chain that converts photonic excitation into a charge separation. The eukaryotic PSI reaction center is composed of at least 11 subunits.
end case
case <OG:Chloroplast>
SUBCELLULAR LOCATIONPlastid, chloroplast thylakoid membrane; Multi- pass membrane protein.
else case <OC:Gloeobacter>
SUBCELLULAR LOCATIONCell inner membrane; Multi-pass membrane protein.
else
SUBCELLULAR LOCATIONCellular thylakoid membrane; Multi-pass membrane protein.
end case
SIMILARITYBelongs to the PsaA/PsaB family.

Keywords [?]

Transport
Electron transport
Photosynthesis
case <OC:Gloeobacter>
Cell membrane
Cell inner membrane
else
Thylakoid
end case
Photosystem I
Chromophore
Chlorophyll
Oxidoreductase
Metal-binding
Iron
Magnesium
Iron-sulfur
4Fe-4S
Membrane
Transmembrane
Transmembrane helix

Gene Ontology [?]

GO:0009055; Molecular function:electron transfer activity
GO:0000287; Molecular function:magnesium ion binding
GO:0015979; Biological process:photosynthesis
case <OG:Chloroplast>
GO:0009535; Cellular component:chloroplast thylakoid membrane
else case <OCellular component:Gloeobacter>
GO:0005886; Cellular component:plasma membrane
else; https://www.ebi.ac.uk/QuickGO/term/else
GO:0042651; Cellular component:thylakoid membrane
end case

Cross-references [?]

Pfam PF00223; PsaA_PsaB; 1;
PIRSF PIRSF002905; PSI_A; 1;
PRINTS PR00257; PHOTSYSPSAAB; 1;
NCBIfam TIGR01335; PsaA; 1;
PROSITE PS00419; PHOTOSYSTEM_I_PSAAB; 1;

Features [?]

From: PSAA_THEVB (P0A405)
Key From To Description Tag Condition FTGroup
TRANSMEM 72 95 /note="Helical; Name=I"
TRANSMEM 158 181 /note="Helical; Name=II"
TRANSMEM 197 221 /note="Helical; Name=III"
TRANSMEM 297 315 /note="Helical; Name=IV"
TRANSMEM 352 375 /note="Helical; Name=V"
TRANSMEM 391 417 /note="Helical; Name=VI"
TRANSMEM 439 461 /note="Helical; Name=VII"
TRANSMEM 536 554 /note="Helical; Name=VIII"
TRANSMEM 594 615 /note="Helical; Name=IX"
TRANSMEM 669 691 /note="Helical; Name=X"
TRANSMEM 729 749 /note="Helical; Name=XI"
BINDING 578 578 /ligand="[4Fe-4S] cluster"
/ligand_id="ChEBI:CHEBI:49883"
/ligand_note="ligand shared between dimeric partners"		 C
BINDING 587 587 /ligand="[4Fe-4S] cluster"
/ligand_id="ChEBI:CHEBI:49883"
/ligand_note="ligand shared between dimeric partners"		 C
case not <OC:Prochlorococcus>
BINDING 680 680 /ligand="chlorophyll a'"
/ligand_id="ChEBI:CHEBI:189419"
/ligand_label="A1"
/ligand_part="Mg"
/ligand_part_id="ChEBI:CHEBI:25107"
/note="axial binding residue"		 H
BINDING 688 688 /ligand="chlorophyll a"
/ligand_id="ChEBI:CHEBI:58416"
/ligand_label="A3"
/ligand_part="Mg"
/ligand_part_id="ChEBI:CHEBI:25107"
/note="axial binding residue"		 M
BINDING 696 696 /ligand="chlorophyll a"
/ligand_id="ChEBI:CHEBI:58416"
/ligand_label="A3"		 Y
end case
case <OC:Prochlorococcus>
BINDING 680 680 /ligand="divinylchlorophyll a'"
/ligand_id="ChEBI:CHEBI:189420"
/ligand_label="A1"
/ligand_part="Mg"
/ligand_part_id="ChEBI:CHEBI:25107"
/note="axial binding residue"		 H
BINDING 688 688 /ligand="divinyl chlorophyll a"
/ligand_id="ChEBI:CHEBI:73095"
/ligand_label="A3"
/ligand_part="Mg"
/ligand_part_id="ChEBI:CHEBI:25107"
/note="axial binding residue"		 M
BINDING 696 696 /ligand="divinyl chlorophyll a"
/ligand_id="ChEBI:CHEBI:73095"
/ligand_label="A3"		 Y
end case
BINDING 697 697 /ligand="phylloquinone"
/ligand_id="ChEBI:CHEBI:18067"
/ligand_label="A"		 W

Additional information [?]

Size range 678-783 amino acids
Related rules None
Fusion Nter: None Cter: None



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