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A2BTA0 · PSAA_PROMS

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/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.

Catalytic activity

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.

Features

Showing features for binding site.

TypeIDPosition(s)Description
Binding site600[4Fe-4S] cluster (UniProtKB | ChEBI); ligand shared between dimeric partners
Binding site609[4Fe-4S] cluster (UniProtKB | ChEBI); ligand shared between dimeric partners
Binding site692Mg (UniProtKB | ChEBI) of divinylchlorophyll a' A1 (UniProtKB | ChEBI); axial binding residue
Binding site700Mg (UniProtKB | ChEBI) of divinyl chlorophyll a A3 (UniProtKB | ChEBI); axial binding residue
Binding site708divinyl chlorophyll a A3 (UniProtKB | ChEBI)
Binding site709phylloquinone A (UniProtKB | ChEBI)

GO annotations

AspectTerm
Cellular Componentphotosystem I
Cellular Componentplasma membrane-derived thylakoid membrane
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 A1
  • EC number
  • Alternative names
    • PsaA

Gene names

    • Name
      psaA
    • Ordered locus names
      A9601_17281

Organism names

Accessions

  • Primary accession
    A2BTA0

Proteomes

Subcellular Location

Features

Showing features for transmembrane.

TypeIDPosition(s)Description
Transmembrane76-99Helical; Name=I
Transmembrane162-185Helical; Name=II
Transmembrane201-225Helical; Name=III
Transmembrane309-327Helical; Name=IV
Transmembrane368-391Helical; Name=V
Transmembrane407-433Helical; Name=VI
Transmembrane455-477Helical; Name=VII
Transmembrane558-576Helical; Name=VIII
Transmembrane616-637Helical; Name=IX
Transmembrane681-703Helical; Name=X
Transmembrane741-761Helical; Name=XI

Keywords

PTM/Processing

Features

Showing features for chain.

TypeIDPosition(s)Description
ChainPRO_00002941991-767Photosystem I P700 chlorophyll a apoprotein A1

Interaction

Subunit

The 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.

Protein-protein interaction databases

Structure

Family & Domains

Features

Showing features for region.

TypeIDPosition(s)Description
Region1-22Disordered

Sequence similarities

Belongs to the PsaA/PsaB family.

Keywords

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    767
  • Mass (Da)
    84,373
  • Last updated
    2007-02-20 v1
  • MD5 Checksum
    C87187F0ED2B22A84DDF0F671EDEBCF2
MTISPPESGEKNKKVLEDPVKADPRPIDFAKLDKPGFWSSKLSKGPKTTTWIWNLHADAHDFDVHTGDAEEATRKIFSAHFGHLAVIFIWMSAAFFHGARFSNYSGWLADPTHVKPGAQQVWAIVGQEMLNADLGANYNGIQISSGIFHMWRAWGITNESELMALAIGAVVMAALMLHAGIFHYHKAAPKMEWFQDIESMLNHHIAGLVGLGSLAWAGHCIHIGAPTAALLDAIDAGSPLVINGKEIATIADMPMPHQLCDPQIIGQIFPGLASGTGNFFSLNWLAFSDFLTFKGGLNPVTGSLWMTDVSHHHLAFGVIAIIGGHMYRTNYGIGHSMKEILDSQQGDPILFPAPKGHQGLFEFMAESRHAQLSVNLAMLGSISILVSHHMYAMPPYPYIATDYMTVLGLFTHHMWIGGLFIVGAGAHAGIAMVRDYDPAKHIDNVLDRILKARDALISHLNWVCMWLGFHSFGLYIHNDTMRALGRPQDMFSDSAIQLQPIFAQWVQSIQASAVGTFLLAGTSEALPHKALSEVFNGSLVEVGGKVAIAPIPLGTADLMIHHIHAFQIHVTVLILLKGVLYARSSRLIPDKASLGFRFPCDGPGRGGTCQVSSWDHVFLALFWMYNCLSIVIFHFSWKMQSDVWGLTGGNFAQSSITINGWLRDFLWAQASQVLTSYGQSISMYGLMFLGAHFIWAFSLMFLFSGRGYWQELFESIVWAHNKLKVAPTIQPRALSITQGRAVGVTHFLVGGIATTWAFFHARLFGLG

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
CP000551
EMBL· GenBank· DDBJ
ABM71011.1
EMBL· GenBank· DDBJ
Genomic DNA

Genome annotation databases

Similar Proteins

Disclaimer

Any medical or genetic information present in this entry is provided for research, educational and informational purposes only. It is not in any way intended to be used as a substitute for professional medical advice, diagnosis, treatment or care. Our staff consists of biologists and biochemists that are not trained to give medical advice.
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