B2XT21 · PSBD_HETA2

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.

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. The PSII complex binds additional chlorophylls, carotenoids and specific lipids.

Features

Showing features for binding site.

TypeIDPosition(s)Description
Binding site116Mg (UniProtKB | ChEBI) of chlorophyll a ChlzD2 (UniProtKB | ChEBI); axial binding residue
Binding site128pheophytin a D2 (UniProtKB | ChEBI)
Binding site141pheophytin a D2 (UniProtKB | ChEBI)
Binding site196Mg (UniProtKB | ChEBI) of chlorophyll a PD2 (UniProtKB | ChEBI); axial binding residue
Binding site213a plastoquinone Q(A) (UniProtKB | ChEBI)
Binding site213Fe cation (UniProtKB | ChEBI); ligand shared with heterodimeric partner
Binding site260a plastoquinone Q(A) (UniProtKB | ChEBI)
Binding site267Fe cation (UniProtKB | ChEBI); ligand shared with heterodimeric partner

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
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 Q(A) protein

Gene names

    • Name
      psbD1
    • Ordered locus names
      Heak293_Cp012
    • Name
      psbD2
    • Ordered locus names
      Heak293_Cp056

Encoded on

  • Chloroplast

Organism names

Accessions

  • Primary accession
    B2XT21

Subcellular Location

Features

Showing features for transmembrane.

TypeIDPosition(s)Description
Transmembrane39-59Helical
Transmembrane123-139Helical
Transmembrane151-164Helical
Transmembrane206-226Helical
Transmembrane277-293Helical

Keywords

PTM/Processing

Features

Showing features for chain.

TypeIDPosition(s)Description
ChainPRO_00003597071-351Photosystem 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, at least 3 peripheral proteins of the oxygen-evolving complex and a large number of cofactors. It forms dimeric complexes.

Structure

Family & Domains

Sequence similarities

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

Keywords

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    351
  • Mass (Da)
    39,122
  • Last updated
    2008-07-01 v1
  • Checksum
    356DAC569B034598
MTIAIGQNQERGVFDLVDDWLKRDRFVFVGWSGLLLFPTAYLAVGGWFTGTTFVTSWYTHGLASSYLEGCNFLTAAVSTPANSMGHSLILLWGPEAQGDFTRWCQIGGLWTFVALHGAFGLIGFCLRQFEIARLVGIRPYNAIAFSGPISIFVSVFLLYPLGQASWFFAPSFGVAAIFRFLLFLQGFHNWTLNPFHMMGVAGILGGALLCAIHGATVENTLFEDGDAANTFRAFTPTQSEETYSMVTANRFWSQIFGVAFSNKRWLHFFMLFVPVTGLWTSAIGIVGLALNLRAYDFVSQELRAAEDPEFETFYTKNILLNEGIRAWMAAQDQPHENFVFPEEVLPRGNAL

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
EU168190
EMBL· GenBank· DDBJ
ABV65919.1
EMBL· GenBank· DDBJ
Genomic DNA
EU168190
EMBL· GenBank· DDBJ
ABV65963.1
EMBL· GenBank· DDBJ
Genomic DNA

Genome annotation databases

Similar Proteins

Disclaimer

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