A4GYR0 · PSAA_POPTR

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 site573[4Fe-4S] cluster (UniProtKB | ChEBI); ligand shared between dimeric partners
Binding site582[4Fe-4S] cluster (UniProtKB | ChEBI); ligand shared between dimeric partners
Binding site675Mg (UniProtKB | ChEBI) of chlorophyll a' A1 (UniProtKB | ChEBI); axial binding residue
Binding site683Mg (UniProtKB | ChEBI) of chlorophyll a A3 (UniProtKB | ChEBI); axial binding residue
Binding site691chlorophyll a A3 (UniProtKB | ChEBI)
Binding site692phylloquinone A (UniProtKB | ChEBI)

GO annotations

AspectTerm
Cellular Componentchloroplast thylakoid membrane
Cellular Componentphotosystem I
Molecular Function4 iron, 4 sulfur cluster binding
Molecular Functionchlorophyll binding
Molecular Functionelectron transfer activity
Molecular Functionmagnesium ion binding
Molecular FunctionmRNA 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
    • Ordered locus names
      Poptr_cp022

Encoded on

  • Chloroplast

Organism names

Accessions

  • Primary accession
    A4GYR0

Proteomes

Genome annotation databases

Subcellular Location

Features

Showing features for transmembrane.

TypeIDPosition(s)Description
Transmembrane70-93Helical; Name=I
Transmembrane156-179Helical; Name=II
Transmembrane195-219Helical; Name=III
Transmembrane291-309Helical; Name=IV
Transmembrane346-369Helical; Name=V
Transmembrane385-411Helical; Name=VI
Transmembrane433-455Helical; Name=VII
Transmembrane531-549Helical; Name=VIII
Transmembrane589-610Helical; Name=IX
Transmembrane664-686Helical; Name=X
Transmembrane724-744Helical; Name=XI

Keywords

PTM/Processing

Features

Showing features for chain.

TypeIDPosition(s)Description
ChainPRO_00002942301-750Photosystem I P700 chlorophyll a apoprotein A1

Expression

Gene expression databases

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.

Protein-protein interaction databases

Structure

Family & Domains

Sequence similarities

Belongs to the PsaA/PsaB family.

Keywords

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    750
  • Mass (Da)
    83,146
  • Last updated
    2007-04-17 v1
  • Checksum
    14493885D0DC35EB
MIIRSPEPEVKILVDRDPIKTSFEEWARPGHFSRTIAKGPDTTTWIWNLHADAHDFDSHTSDLEEISRKVFSAHFGQLSIIFLWLSGMYFHGARFSNYEAWLSDPTHIGPSAQVVWPIVGQEILNGDVGGGFRGIQITSGFFQIWRASGITSELQLYCTAIGALVFAALMLFAGWFHYHKAAPKLAWFQDVESMLNHHLAGLLGLGSLSWAGHQVHVSLPINQFLNAGVDPKEIPLPHEFILNRDLLAQLYPSFAEGATPFFTLNWSKYSEFLTFRGGLDPVTGGLWLTDIAHHHLAIAILFLVAGHMYRTNWGIGHGIKDILEAHKGPFTGQGHKGLYEILTTSWHAQLSLNLAMLGSLTIVVAHHMYAMPPYPYLATDYGTQLSLFTHHMWIGGFLIVGAAAHAAIFMVRDYDPTTRYNDLLDRVLRHRDAIISHLNWVCIFLGFHSFGLYIHNDTMSALGRPQDMFSDTAIQLQPVFAQWIQNTHALAPGATAPGATASTSLTWGGDDLVAVGGKVALLPIPLGTADFLVHHIHAFTIHVTVLILLKGVLFARSSRLIPDKANLGFRFPCDGPGRGGTCQVSAWDHVFLGLFWMYNAISVVIFHFSWKMQSDVWGSISDQGVVTHITGGNFAQSSITINGWLRDFLWAQASQVIQSYGSSLSAYGLFFLGAHFVWAFSLMFLFSGRGYWQELIESIVWAHNKLKVAPATQPRALSIIQGRAVGVTHYLLGGIATTWAFFLARIIAVG

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
EF489041
EMBL· GenBank· DDBJ
ABO36704.1
EMBL· GenBank· DDBJ
Genomic DNA

Genome annotation databases

Similar Proteins

Disclaimer

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