Essential maintenance is planned to begin on Fri Jan 24 2025. The website may be temporarily unavailable. Please use our fallback: https://wwwdev.ebi.ac.uk/uniprot/front-end/fallback/ in case of any outage.

Q46IV6 · PSAA_PROMT

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 site601[4Fe-4S] cluster (UniProtKB | ChEBI); ligand shared between dimeric partners
Binding site610[4Fe-4S] cluster (UniProtKB | ChEBI); ligand shared between dimeric partners
Binding site693Mg (UniProtKB | ChEBI) of divinylchlorophyll a' A1 (UniProtKB | ChEBI); axial binding residue
Binding site701Mg (UniProtKB | ChEBI) of divinyl chlorophyll a A3 (UniProtKB | ChEBI); axial binding residue
Binding site709divinyl chlorophyll a A3 (UniProtKB | ChEBI)
Binding site710phylloquinone 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
      PMN2A_1082

Organism names

Accessions

  • Primary accession
    Q46IV6

Proteomes

Subcellular Location

Features

Showing features for transmembrane.

TypeIDPosition(s)Description
Transmembrane76-99Helical; Name=I
Transmembrane162-185Helical; Name=II
Transmembrane201-225Helical; Name=III
Transmembrane310-328Helical; Name=IV
Transmembrane369-392Helical; Name=V
Transmembrane408-434Helical; Name=VI
Transmembrane456-478Helical; Name=VII
Transmembrane559-577Helical; Name=VIII
Transmembrane617-638Helical; Name=IX
Transmembrane682-704Helical; Name=X
Transmembrane742-762Helical; Name=XI

Keywords

PTM/Processing

Features

Showing features for chain.

TypeIDPosition(s)Description
ChainPRO_00002942051-768Photosystem 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

Sequence similarities

Belongs to the PsaA/PsaB family.

Keywords

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    768
  • Mass (Da)
    84,363
  • Last updated
    2005-09-13 v1
  • MD5 Checksum
    0D047014134A643F94D6A6B52C54C046
MTISPPEKEQKKEPVLDKPIETDAIPVDFSKLDKPGFWSKSLAKGPKTTTWIWNLHADAHDFDTHVGDLQETSRKVFSAHFGHLAVIFIWMSAAFFHGARFSNYSGWLSDPTHVKPGAQVVWPIVGQEMLNADLGGNYHGIQITSGIFQMWRGWGITNETELMALAIGALLMAAIMLHGGIYHYHKAAPKLDWFRNLESMLNHHIAGLVGLGSIAWAGHCIHIGAPTAALMDAIDAGKPLIIDGIPIASIADMPLPHELCNPAIASQIFPGLAGRTVENFFTTNWWAFSDFLTFKGGLNPVTGSLWMTDISHHHLAFGVLAVLGGHLYRTMFGIGHSLKEILDNHAGDPILFPAPNGHKGIYEFLANSWHAQLGLNLAMIGSLSIIISHHMYAMPPYPYLSIDYPTVLGLFTHHMWIGGLFIVGAAAHAGIAMIRDYDPAVHIDNVLDRILKARDALISHLNWACMFLGFHSFGLYIHNDVMRALGRPADMFSDTGIQLQPVFAQWIQNIHNSAAGSTTLAGANVSLQPGLVSEVFNGSVSQVGGKIGIAPIPLGTADFMIHHIHAFTIHVTLLILLKGVLFARSSRLIPDKANLGFRFPCDGPGRGGTCQVSSWDHVFLGLFWMYNGLSVVIFHFSWKMQSDVWGLTGGNFAQSSITINGWLRDFLWAQSSQVLTSYGQPISMYGLMFLGAHFVWAFSLMFLFSGRGYWQELFESIIWAHNKLNLAPTIQPRALSITQGRAVGAAHFLLGGIATTWAFFHARLIGLG

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
CP000095
EMBL· GenBank· DDBJ
AAZ58572.1
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.
We'd like to inform you that we have updated our Privacy Notice to comply with Europe’s new General Data Protection Regulation (GDPR) that applies since 25 May 2018.
Help