A0A6G7KWS6 · A0A6G7KWS6_9ASPA

Function

function

Photosystem II (PSII) is a light-driven water:plastoquinone oxidoreductase that uses light energy to abstract electrons from H2O, generating O2 and a proton gradient subsequently used for ATP formation. It consists of a core antenna complex that captures photons, and an electron transfer chain that converts photonic excitation into a charge separation. The D1/D2 (PsbA/PsbD) reaction center heterodimer binds P680, the primary electron donor of PSII as well as several subsequent electron acceptors.

Miscellaneous

2 of the reaction center chlorophylls (ChlD1 and ChlD2) are entirely coordinated by water.
Herbicides such as atrazine, BNT, diuron or ioxynil bind in the Q(B) binding site and block subsequent electron transfer.

Catalytic activity

Features

Showing features for binding site, site.

TypeIDPosition(s)Description
Binding site118Mg (UniProtKB | ChEBI) of chlorophyll a ChlzD1 (UniProtKB | ChEBI); axial binding residue
Binding site126pheophytin a D1 (UniProtKB | ChEBI)
Site161Tyrosine radical intermediate
Binding site170[CaMn4O5] cluster (UniProtKB | ChEBI)
Binding site189[CaMn4O5] cluster (UniProtKB | ChEBI)
Site190Stabilizes free radical intermediate
Binding site198Mg (UniProtKB | ChEBI) of chlorophyll a PD1 (UniProtKB | ChEBI); axial binding residue
Binding site215Fe cation (UniProtKB | ChEBI); ligand shared with heterodimeric partner
Binding site215a quinone B (UniProtKB | ChEBI)
Binding site264-265a quinone B (UniProtKB | ChEBI)
Binding site272Fe cation (UniProtKB | ChEBI); ligand shared with heterodimeric partner
Binding site332[CaMn4O5] cluster (UniProtKB | ChEBI)
Binding site333[CaMn4O5] cluster (UniProtKB | ChEBI)
Binding site342[CaMn4O5] cluster (UniProtKB | ChEBI)
Binding site344[CaMn4O5] cluster (UniProtKB | ChEBI)
Site344-345Cleavage; by CtpA

GO annotations

AspectTerm
Cellular Componentchloroplast thylakoid membrane
Cellular Componentphotosystem II
Molecular Functionchlorophyll binding
Molecular Functionelectron transporter, transferring electrons within the cyclic electron transport pathway of photosynthesis activity
Molecular Functioniron ion binding
Molecular Functionoxidoreductase activity, acting on diphenols and related substances as donors, oxygen as acceptor
Molecular Functionoxygen evolving activity
Biological Processphotosynthetic electron transport in photosystem II
Biological Processresponse to herbicide

Keywords

Enzyme and pathway databases

Names & Taxonomy

Protein names

  • Recommended name
    Photosystem II protein D1
  • EC number
  • Short names
    PSII D1 protein
  • Alternative names
    • Photosystem II Q(B) protein

Gene names

    • Name
      psbA

Encoded on

  • Chloroplast

Organism names

  • Taxonomic identifier
  • Organism
  • Taxonomic lineage
    Eukaryota > Viridiplantae > Streptophyta > Embryophyta > Tracheophyta > Spermatophyta > Magnoliopsida > Liliopsida > Asparagales > Orchidaceae > Orchidoideae > Orchideae > Orchidinae > Platanthera

Accessions

  • Primary accession
    A0A6G7KWS6

Subcellular Location

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

Features

Showing features for transmembrane.

TypeIDPosition(s)Description
Transmembrane29-55Helical
Transmembrane76-97Helical
Transmembrane109-129Helical
Transmembrane141-161Helical
Transmembrane167-186Helical
Transmembrane198-218Helical
Transmembrane273-295Helical

Keywords

PTM/Processing

Features

Showing features for initiator methionine, modified residue, chain, propeptide.

TypeIDPosition(s)Description
Initiator methionine1Removed
Modified residue2N-acetylthreonine
Modified residue2Phosphothreonine
ChainPRO_50263975672-344Photosystem II protein D1
PropeptidePRO_5026397568345-353

Post-translational modification

C-terminally processed by CtpA; processing is essential to allow assembly of the oxygen-evolving complex and thus photosynthetic growth.
Tyr-161 forms a radical intermediate that is referred to as redox-active TyrZ, YZ or Y-Z.

Keywords

Interaction

Subunit

PSII is composed of 1 copy each of membrane proteins PsbA, PsbB, PsbC, PsbD, PsbE, PsbF, PsbH, PsbI, PsbJ, PsbK, PsbL, PsbM, PsbT, PsbX, PsbY, PsbZ, Psb30/Ycf12, at least 3 peripheral proteins of the oxygen-evolving complex and a large number of cofactors. It forms dimeric complexes.

Family & Domains

Sequence similarities

Belongs to the reaction center PufL/M/PsbA/D family.

Keywords

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    353
  • Mass (Da)
    38,936
  • Last updated
    2020-08-12 v1
  • Checksum
    A5C55EBE5FDD937A
MTAILERRESTSLWGRFCNWITSTENRLYIGWFGVLMIPTLLTATSVFIIAFIAAPPVDIDGIREPVSGSLLYGNNIISGAIIPTSAAIGLHFYPIWEAASVDEWLYNGGPYELIVLHFLLGVACYMGREWELSFRLGMRPWIAVAYSAPVAAATAVFLIYPIGQGSFSDGMPLGISGTFNFMIVFQAEHNILMHPFHMLGVAGVFGGSLFSAMHGSLVTSSLIRETTENESANEGYRFGQEGETYNIVAAHGYFGRLIFQYASFNNSRSLHFFLAAWPVVGIWFTALGISTMAFNLNGFNFNQSVVDSQGRVINTWADIINRANLGMEVMHERNAHNFPLDLASVEVPSRNG

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
MN200370
EMBL· GenBank· DDBJ
QII89817.1
EMBL· GenBank· DDBJ
Genomic DNA

Similar Proteins

Disclaimer

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