Q9MUJ6 · PSAA_EQUPA

Function

function

PsaA 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.

Catalytic activity

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.

Features

Showing features for binding site.

TypeIDPosition(s)Description
Binding site563[4Fe-4S] cluster (UniProtKB | ChEBI); ligand shared between dimeric partners
Binding site572[4Fe-4S] cluster (UniProtKB | ChEBI); ligand shared between dimeric partners
Binding site665Mg (UniProtKB | ChEBI) of chlorophyll a' A1 (UniProtKB | ChEBI); axial binding residue
Binding site673Mg (UniProtKB | ChEBI) of chlorophyll a A3 (UniProtKB | ChEBI); axial binding residue
Binding site681chlorophyll a A3 (UniProtKB | ChEBI)
Binding site682phylloquinone A (UniProtKB | ChEBI)

GO annotations

AspectTerm
Cellular Componentchloroplast thylakoid membrane
Cellular Componentphotosystem I
Molecular Function4 iron, 4 sulfur cluster binding
Molecular Functionchlorophyll binding
Molecular Functionmetal ion binding
Molecular Functionoxidoreductase activity
Biological Processphotosynthesis

Keywords

Enzyme and pathway databases

Names & Taxonomy

Protein names

  • Recommended name
    Photosystem I P700 chlorophyll a apoprotein A1
  • EC number
  • Alternative names
    • PSI-A
    • PsaA

Gene names

    • Name
      psaA

Encoded on

  • Chloroplast

Organism names

Accessions

  • Primary accession
    Q9MUJ6

Subcellular Location

Features

Showing features for transmembrane.

TypeIDPosition(s)Description
Transmembrane60-83Helical; Name=I
Transmembrane146-169Helical; Name=II
Transmembrane185-209Helical; Name=III
Transmembrane281-299Helical; Name=IV
Transmembrane336-359Helical; Name=V
Transmembrane375-401Helical; Name=VI
Transmembrane423-445Helical; Name=VII
Transmembrane521-539Helical; Name=VIII
Transmembrane579-600Helical; Name=IX
Transmembrane654-676Helical; Name=X
Transmembrane714-719Helical; Name=XI

Keywords

PTM/Processing

Features

Showing features for chain.

TypeIDPosition(s)Description
ChainPRO_00000885481-719Photosystem I P700 chlorophyll a apoprotein A1

Interaction

Subunit

The 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.

Structure

Family & Domains

Sequence similarities

Belongs to the PsaA/PsaB family.

Keywords

Family and domain databases

Sequence

  • Sequence status
    Fragment
  • Length
    719
  • Mass (Da)
    79,913
  • Last updated
    2000-10-01 v1
  • Checksum
    A356DAADC0CF24D0
KIIVEKDPVRTSFEKWAQPGHFSKTLAKGPNTTTWIWNLHADAHDFDSHTNDLEDISRKIFSAHFGQLSIIFIWLSGMYFHGARFSNYEAWLSDPTHIKPSAQVVWPIVGQEILNGDVGGGFQGIQITSGFFQLWRASGITNELQLYCTAIGALIFAGLMLFAGWFHYHKAAPKLAWFQDVESMLNHHLAGLLGLGSLGWAGHQVHVSLPINQLLDSGVDPREIPLPHEFILNRDLLAQLYPSFSEGLTPFFNLEWSKYSDFLTFRGGLNPVTGGLWLTDTAHHHIAIAVLFLIAGHMYRTNWGIGHSIKEILEAHKGPFTGEGHRGLFEILTSSWHAQLAVNLAMLGSLTIIVAHHMYAMPPYPYLATDYGTQLSLFTHHMWIGGFLVVGAAAHAAIFMVRDYDPSTQYNNLLDRVIRHRDAIISHLNWVCIFLGFHSFGLYIHNDTMSALGRPQDMFSDTAIQLQPIFAQWIQNTHALAPSLTAPNATASTSLTWGGGDLVSVGGRVALLPIPLGTADFLVHHIHAFTIHVTVLILLKGVLFARSSRLIPDKANLGFRFPCDGPGRGGTCQVSAWDHVFLGLFWMYNSISVVIFHFSWKMQSDVWGSINEQGVISHITGGNFAQSATTINGWLRDFLWAQASQVIQSYGSSLSAYGLLFLGAHFVWAFSLMFLFSGRGYWQELIESILWAHNKLKVAPAIQPRALSIVQGRAVGVAH

Features

Showing features for non-terminal residue.

TypeIDPosition(s)Description
Non-terminal residue1
Non-terminal residue719

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
AF180019
EMBL· GenBank· DDBJ
AAF29820.1
EMBL· GenBank· DDBJ
Genomic DNA

Similar Proteins

Disclaimer

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