A0A2U9NSS3 · A0A2U9NSS3_9STRA

  • 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/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

Features

Showing features for binding site.

1733100200300400500600700
TypeIDPosition(s)Description
Binding site558[4Fe-4S] cluster (UniProtKB | ChEBI); ligand shared between dimeric partners
Binding site567[4Fe-4S] cluster (UniProtKB | ChEBI); ligand shared between dimeric partners
Binding site653Mg (UniProtKB | ChEBI) of chlorophyll a B1 (UniProtKB | ChEBI); axial binding residue
Binding site661Mg (UniProtKB | ChEBI) of chlorophyll a B3 (UniProtKB | ChEBI); axial binding residue
Binding site669chlorophyll a B3 (UniProtKB | ChEBI)
Binding site670phylloquinone B (UniProtKB | ChEBI)

GO annotations

all annotationsall molecular functionvirus receptor activitydna bindingrna bindingcytoskeletal motor activitycatalytic activitygtpase activitystructural molecule activitytransporter activitycytoskeletal protein bindinglipid bindingcyclase activityantioxidant activityoxidoreductase activitytransferase activityhydrolase activitylyase activityisomerase activityligase activityprotein tag activitycargo receptor activityhistone bindingprotein folding chaperonetranslation regulator activitynutrient reservoir activityreceptor ligand activitymolecular transducer activitymolecular adaptor activitytoxin activitycell adhesion mediator activitymolecular function regulator activityvirus coreceptor activitycatalytic activity, acting on a proteincatalytic activity, acting on dnacatalytic activity, acting on rnamolecular carrier activitytranscription regulator activitygeneral transcription initiation factor activitymolecular sensor activitymolecular sequestering activityatp-dependent activityother molecular functionall biological processmitotic cell cyclecytokinesiscytoplasmic translationimmune system processmuscle system processcirculatory system processrenal system processrespiratory system processcarbohydrate metabolic processgeneration of precursor metabolites and energydna replicationdna repairdna recombinationchromatin organizationdna-templated transcriptionregulation of dna-templated transcriptiontrna metabolic processprotein foldingprotein glycosylationamino acid metabolic processmodified amino acid metabolic processlipid metabolic processvitamin metabolic processsulfur compound metabolic processintracellular protein transportnucleocytoplasmic transportautophagyinflammatory responsemitochondrion organizationcytoskeleton organizationmicrotubule-based movementperoxisome organizationlysosome organizationchromosome segregationcell adhesionestablishment or maintenance of cell polarityprogrammed cell deathphotosynthesismrna metabolic processsnrna metabolic processvesicle-mediated transportreproductive processdigestive system processsignalingcell differentiationprotein catabolic processextracellular matrix organizationregulatory ncrna-mediated gene silencingtelomere organizationcell junction organizationwound healingribosome biogenesiscilium organizationanatomical structure developmentcell motilitynervous system processendocrine processprotein maturationtransmembrane transportnucleobase-containing small molecule metabolic processhepaticobiliary system processmembrane organizationprotein-containing complex assemblycell wall organization or biogenesisnitrogen cycle metabolic processprotein localization to plasma membranedefense response to other organismdetoxificationmeiotic nuclear divisionmitotic nuclear divisionmitochondrial gene expressioncarbohydrate derivative metabolic processother biological processall cellular componentnuclear chromosomeextracellular regionextracellular spacecell wallnucleusnuclear envelopenucleoplasmchromosomenucleolusmitochondrionlysosomeendosomevacuoleperoxisomeendoplasmic reticulumgolgi apparatuslipid dropletmicrotubule organizing centercytosolribosomecytoskeletonplasma membraneciliumplastidthylakoidexternal encapsulating structureextracellular matrixcytoplasmic vesicleorganelleother cellular component
Cell color indicative of number of GO terms
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 > Sar > Stramenopiles > Ochrophyta > Bacillariophyta > Mediophyceae > Biddulphiophycidae > Biddulphiales > Biddulphiaceae > Biddulphia

Accessions

  • Primary accession
    A0A2U9NSS3

Subcellular Location

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

Features

Showing features for transmembrane.

TypeIDPosition(s)Description
Transmembrane51-70Helical
Transmembrane138-156Helical
Transmembrane272-290Helical
Transmembrane333-354Helical
Transmembrane374-395Helical
Transmembrane416-437Helical
Transmembrane517-538Helical
Transmembrane574-595Helical
Transmembrane644-664Helical
Transmembrane706-726Helical

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
    733
  • Mass (Da)
    82,093
  • Last updated
    2018-09-12 v1
  • Checksum
    2298C693A2467BE5
MATKFPKFSQALAQDPATRRIWYGIATAHDLEAHDGMTEENLYQKIFASHFGHLAIIFLWTSGNLFHVAWQGNFEKWVNNPLKTKPIAHSIWDPHFGESALKAFSKGNTYPVNIAFSGVYQWWYTIGFRTNQELYKGSLGLLLFSCVLLIAGWLHLQPKFRPSLSWFKNNESRLNHHLSGMLGVSSLAWTGHLVHVAIPASRGVHVGWDNFLTTPPHPAGLEPFFTGNWTVYAQNPDTPNHIYGTSEGAGTAILTFLGGFHPQTQSLWLSDIAHHQLAIAVVFIIAGHMYRTNFGIGHNMKEILDAHRPPGGRLGAGHTGLFETITNSLHMQLGLALACLGVATSLTAQHMYALTPYAFLSKDFTTEAALYTHHQYIAGFLMVGAFAHGAIFFVRDYDPELNKNNVLARMLEHKEAIISHLSWASLFLGFHTLGLYIHNDTVVAFGQPEKQILFEPVFAEYIQAASGKAIYNFNVLLSSSTSPATVAGNQVWLPGWLEAINNSKNDLFLKIGPGDFLVHHAIALGLHVTTLILVKGALDARGSKLMPDKKDFGYSFPCDGPGRGGTCDISAWDAFYLAMFWMLNTIGWVTFYWHWKHMTIWGGNPGQFDESSNYIMGWLRDYLWLNSSPLINGYNPFGMNNLSVWAWMFLFGHLIWATGFMFLISWRGYWQELIETLVWAHERTPLANLVRWRDKPVALSIVQARLVGLVHFAVGYILTYAAFVIASTSGKFG

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
MG755806
EMBL· GenBank· DDBJ
AWT40138.1
EMBL· GenBank· DDBJ
Genomic DNA

Similar Proteins

Disclaimer

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