A0A9E8AH99 · A0A9E8AH99_9LILI

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.

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

Accessions

  • Primary accession
    A0A9E8AH99

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
Transmembrane334-355Helical
Transmembrane375-395Helical
Transmembrane416-438Helical
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)
    82,605
  • Last updated
    2023-05-03 v1
  • Checksum
    B242B6C7717DD885
MALRFPKFSQGLAQDPTTRRIWFGIATAHDFESHDDITEERLYQNIFASHFGQLAIIFLWTSGNLFHVAWQGNFESWIQDPLHVRPIAHAIWDPHFGQPAVEAFTRGGALGPVNIAYSGVYQWWYTIGLRTNEDLYTGALFLLFLSAISFIAGWLHLQPKWKPSVSWFKNAESRLNHHLSGLFGVSSLAWAGHLVHVAIPASRGEYVRWKNFLDVLPYPQGLGPLFTGQWNLYAQNPDSSSHLFGTYQGAGTAILTLLGGFHPQTQSLWLTDIAHHHLAIAFLFLIAGHMYRTNFGIGHSIKDLLEAHIPPGGRLGRGHKGLYDTINNSIHFQLGLALASLGVITSLVAQHMYSLPAYAFLAQDFTTQAALYTHHQYIAGFIMTGAFAHGALFFIRDYNPEKNEDNVLARMLDHKEAIISHLSWASLFLGFHTLGLYVHNDVMLAFGTPEKEILIEPIFAQWIQSAHGKTSYGFDLLLSSTDGPAFNAGRNIWLSGWLNAVNENGNSLFLTIGPGDFLVHHAIALGLHTTTLILVKGALDARGSKLMPDKKDFGYSFPCDGPGRGGTCDISAWDAFYLAVFWMLNTIGWVTFYWHWKHITLWQGNVSQFQESSTYLMGWLRDYLWLNSSQLINGYNPFGMNSLSVWAWMFLFGHLVWATGFMFLISWRGYWQELIETLAWAHERTPLANFLRWRDKPVALSIVQARLVGLAHFSVGYIFTYAAFLIASTSGKFG

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
OM630415
EMBL· GenBank· DDBJ
UZC33391.1
EMBL· GenBank· DDBJ
Genomic DNA

Similar Proteins

Disclaimer

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