Q8CM25 · PSBD_THEVB

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. D2 is needed for assembly of a stable PSII complex.

Miscellaneous

2 of the reaction center chlorophylls (ChlD1 and ChlD2) are entirely coordinated by water.

Caution

According to (Ref.2, PubMed:22665786, PubMed:23413188, PubMed:25006873) there are no direct protein ligands to pheophytin D2, whereas (PubMed:14764885, PubMed:16355230, PubMed:19219048, PubMed:20558739, PubMed:21367867, PubMed:25043005) show 1 or 2 direct ligands.

Catalytic activity

Cofactor

Note: The D1/D2 heterodimer binds P680, chlorophylls that are the primary electron donor of PSII, and subsequent electron acceptors. It shares a non-heme iron and each subunit binds pheophytin, quinone, additional chlorophylls, carotenoids and lipids. There is also a Cl-1 ion associated with D1 and D2, which is required for oxygen evolution (PubMed:19219048, PubMed:21367867).
PSII binds additional chlorophylls, carotenoids and specific lipids.

Features

Showing features for binding site.

TypeIDPosition(s)Description
Binding site117Mg (UniProtKB | ChEBI) of chlorophyll a ChlzD2 (UniProtKB | ChEBI); axial binding residue
Binding site129pheophytin a D2 (UniProtKB | ChEBI)
Binding site142pheophytin a D2 (UniProtKB | ChEBI)
Binding site197Mg (UniProtKB | ChEBI) of chlorophyll a PD2 (UniProtKB | ChEBI); axial binding residue
Binding site214a plastoquinone Q(A) (UniProtKB | ChEBI)
Binding site214Fe cation (UniProtKB | ChEBI); ligand shared with heterodimeric partner
Binding site261a plastoquinone Q(A) (UniProtKB | ChEBI)
Binding site268Fe cation (UniProtKB | ChEBI); ligand shared with heterodimeric partner

GO annotations

AspectTerm
Cellular Componentphotosystem II
Cellular Componentplasma membrane-derived thylakoid membrane
Molecular Functionchlorophyll binding
Molecular Functionelectron transporter, transferring electrons within the cyclic electron transport pathway of photosynthesis activity
Molecular Functioniron ion binding
Molecular Functionoxygen evolving activity
Biological Processphotosynthetic electron transport in photosystem II

Keywords

Enzyme and pathway databases

Names & Taxonomy

Protein names

  • Recommended name
    Photosystem II D2 protein
  • EC number
  • Short names
    PSII D2 protein
  • Alternative names
    • Photosystem II Q(A) protein

Gene names

    • Name
      psbD1
    • Ordered locus names
      tlr0455
    • Name
      psbD2
    • Ordered locus names
      tlr1630

Organism names

Accessions

  • Primary accession
    Q8CM25

Proteomes

Subcellular Location

Cellular thylakoid membrane
; Multi-pass membrane protein

Features

Showing features for topological domain, transmembrane.

TypeIDPosition(s)Description
Topological domain1-31Cytoplasmic
Transmembrane32-53Helical
Topological domain54-108Lumenal
Transmembrane109-131Helical
Topological domain132-140Cytoplasmic
Transmembrane141-160Helical
Topological domain161-193Lumenal
Transmembrane194-217Helical
Topological domain218-265Cytoplasmic
Transmembrane266-288Helical
Topological domain289-352Lumenal

Keywords

PTM/Processing

Features

Showing features for chain.

TypeIDPosition(s)Description
ChainPRO_00003596031-352Photosystem II D2 protein

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, peripheral proteins PsbO, CyanoQ (PsbQ), PsbU, PsbV and a large number of cofactors. It forms dimeric complexes. Part of a photosystem II (PSII) assembly intermediate complex PSII-I; crystallized from a strain deleted of psbJ, it forms monomeric PSII before addition of the oxygen evolving complex. PSII-I includes 3 assembly factors not found in mature PSII (Psb27, Psb28 and Psb34) (PubMed:33846594).

Protein-protein interaction databases

Family & Domains

Sequence similarities

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

Keywords

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    352
  • Mass (Da)
    39,361
  • Last updated
    2003-03-01 v1
  • Checksum
    C5D91543CD148FD4
MTIAIGRAPAERGWFDILDDWLKRDRFVFVGWSGILLFPCAYLALGGWLTGTTFVTSWYTHGLASSYLEGCNFLTVAVSTPANSMGHSLLLLWGPEAQGDFTRWCQLGGLWTFIALHGAFGLIGFMLRQFEIARLVGVRPYNAIAFSAPIAVFVSVFLIYPLGQSSWFFAPSFGVAAIFRFLLFFQGFHNWTLNPFHMMGVAGVLGGALLCAIHGATVENTLFQDGEGASTFRAFNPTQAEETYSMVTANRFWSQIFGIAFSNKRWLHFFMLFVPVTGLWMSAIGVVGLALNLRSYDFISQEIRAAEDPEFETFYTKNLLLNEGIRAWMAPQDQPHENFVFPEEVLPRGNAL

Mass Spectrometry

Molecular mass is 39,290 Da. Determined by MALDI.

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
BA000039
EMBL· GenBank· DDBJ
BAC08007.1
EMBL· GenBank· DDBJ
Genomic DNA
BA000039
EMBL· GenBank· DDBJ
BAC09182.1
EMBL· GenBank· DDBJ
Genomic DNA

Genome annotation databases

Similar Proteins

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