Probable histone H2A variant 3 (At1g52740) is a 134-residue protein from Arabidopsis thaliana. This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: Q9C944.
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The mean pLDDT of this model is 87.8 (confident 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 | 76% |
| 70 to 90 | Confident: backbone generally right | 5% |
| 50 to 70 | Low: treat with caution | 8% |
| Below 50 | Very low: often disordered regions | 11% |
What pLDDT means and how to read it
Variant histones H2A are synthesized throughout the cell cycle and are very different from classical S-phase regulated H2A. May replace conventional H2A in a subset of nucleosomes. Nucleosomes wrap and compact DNA into chromatin, limiting DNA accessibility to the cellular machineries which require DNA as a template. Histones thereby play a central role in transcription regulation, DNA repair, DNA replication and chromosomal stability. DNA accessibility is regulated via a complex set of post-translational modifications of histones, also called histone code, and nucleosome remodeling (By similarity)
The nucleosome is a histone octamer containing two molecules each of H2A, H2B, H3 and H4 assembled in one H3-H4 heterotetramer and two H2A-H2B heterodimers. The octamer wraps approximately 147 bp of DNA
Nucleus, Chromosome
Compare the prediction with experimentally determined structures of the same protein:
| PDB ID | Method | Resolution | Chains and residues |
|---|---|---|---|
| 9K45 | EM | 2.71 Å | C/G=1-134 |
| 9K3Z | EM | 2.75 Å | C/G=1-134 |
| 9K43 | EM | 2.87 Å | C/G=1-134 |
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