Photosystem II D2 protein (psbD) is a 353-residue protein from Spinacia oleracea. This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: P06005.
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The mean pLDDT of this model is 96.3 (very high overall). pLDDT is AlphaFold's per-residue confidence score from 0 to 100. In MolViewer, choose the B-factor color scheme to color the model by pLDDT, because AlphaFold stores it in the B-factor column.
| pLDDT band | Meaning | Share of residues |
|---|---|---|
| Above 90 | Very high: backbone and side chains are usually accurate | 96% |
| 70 to 90 | Confident: backbone generally right | 0% |
| 50 to 70 | Low: treat with caution | 1% |
| Below 50 | Very low: often disordered regions | 3% |
What pLDDT means and how to read it
Photosystem II (PSII) is a light-driven water:plastoquinone oxidoreductase that uses light energy to abstract electrons from H(2)O, generating O(2) 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
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
Plastid, chloroplast thylakoid membrane
Compare the prediction with experimentally determined structures of the same protein:
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