A0A9E9IXH2 · A0A9E9IXH2_9LAMI

  • Protein
    Photosystem I P700 chlorophyll a apoprotein A2
  • Gene
    psaB
  • Status
    UniProtKB unreviewed (TrEMBL)
  • Amino acids
  • Protein existence
    Inferred from homology
  • Annotation score
    3/5

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

Features

Showing features for binding site.

1734100200300400500600700
TypeIDPosition(s)Description
Binding site559[4Fe-4S] cluster (UniProtKB | ChEBI); ligand shared between dimeric partners
Binding site568[4Fe-4S] cluster (UniProtKB | ChEBI); ligand shared between dimeric partners
Binding site654Mg (UniProtKB | ChEBI) of chlorophyll a B1 (UniProtKB | ChEBI); axial binding residue
Binding site662Mg (UniProtKB | ChEBI) of chlorophyll a B3 (UniProtKB | ChEBI); axial binding residue
Binding site670chlorophyll a B3 (UniProtKB | ChEBI)
Binding site671phylloquinone B (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 Functionoxidoreductase activity
Biological Processphotosynthesis

Keywords

Enzyme and pathway databases

Names & Taxonomy

Protein names

  • Recommended name
    Photosystem I P700 chlorophyll a apoprotein A2
  • EC number
  • Alternative names
    • PSI-B
    • PsaB

Gene names

    • Name
      psaB

Encoded on

  • Chloroplast

Organism names

  • Taxonomic identifier
  • Organism
  • Taxonomic lineage
    Eukaryota > Viridiplantae > Streptophyta > Embryophyta > Tracheophyta > Spermatophyta > Magnoliopsida > eudicotyledons > Gunneridae > Pentapetalae > asterids > lamiids > Lamiales > Scrophulariaceae > Buddlejeae > Buddleja

Accessions

  • Primary accession
    A0A9E9IXH2

Subcellular Location

Membrane
; Multi-pass membrane protein
Plastid, chloroplast thylakoid membrane
; Multi-pass membrane protein

Features

Showing features for transmembrane.

TypeIDPosition(s)Description
Transmembrane135-157Helical
Transmembrane178-199Helical
Transmembrane330-349Helical
Transmembrane377-396Helical
Transmembrane417-438Helical
Transmembrane517-539Helical
Transmembrane575-596Helical
Transmembrane645-665Helical
Transmembrane707-727Helical

Keywords

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.

Family & Domains

Sequence similarities

Belongs to the PsaA/PsaB family.

Keywords

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    734
  • Mass (Da)
    82,363
  • Last updated
    2023-05-03 v1
  • Checksum
    C5BAE91E98D7DBE8
MALRFPRFSQGLAQDPTTRRIWFGIATAHDFESHDDITEERLYQNIFASHFGQLAIIFLWTSGNLFHVAWQGNFESWVQDPLHVRPIAHAIWDPHFGQPAVEAFTRGGALGPVNIAYSGVYQWWYTIGLRTNEDLYTGALFLLFLSAISLIAGWLHLQPKWKPSVSWFKNAESRLNHHLSGLFGVSSLAWTGHLVHVAIPGSRGEDVRWNNFLDVLPHPQGLGPLFTGQWNLYAQNPDSSSHLFGTSQGAGTAILTLLGGFHPQTQSLWLTDMAHHHLAIAFIFLVAGHMYRTNFGIGHSIKDLLDAHIPPGGRLGRGHKGLYDTINNSLHFQLGLALASLGVITSLVAQHMYSLPAYAFIAQDFTTQAALYTHHQYIAGFIMTGAFAHGAIFFIRDYNPEQNEDNVLARMLDHKEAIISHLSWASLFLGFHTLGLYVHNDVMLAFGTPEKQILIEPVFAQWIQSAHGKTSYGFDVLLSSTSGPAFNAGRSIWLPGWLNAINENTNSLFLTIGPGDFLVHHAIALGLHTTTLILVKGALDARGSKLMPDKKDFGYSFPCDGPGRGGTCDISAWDAFYLAVFWMLNTIGWVTFYWHWKHITLWQGNVSQFNESSTYLMGWLRDYLWLNSSQLINGYNPFGMNSLSVWAWMFLFGHLVWATGFMFLISWRGYWQELIETLAWAHERTPLANLIRWRDKPVALSIVQARLVGLAHFSVGYIFTYAAFLIASTSGKFG

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
OP007343
EMBL· GenBank· DDBJ
WAN81462.1
EMBL· GenBank· DDBJ
Genomic DNA

Similar Proteins

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