Histone H2A type 2-A (H2AC18) is a 130-residue protein from Homo sapiens. This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: Q6FI13.
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The mean pLDDT of this model is 91.0 (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 | 79% |
| 70 to 90 | Confident: backbone generally right | 7% |
| 50 to 70 | Low: treat with caution | 13% |
| Below 50 | Very low: often disordered regions | 1% |
What pLDDT means and how to read it
Core component of nucleosome. 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
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 |
|---|---|---|---|
| 9D3P | EM | 2.5 Å | C/G=13-119 |
| 9FGQ | EM | 2.5 Å | C/G=1-130 |
| 9D3K | EM | 2.7 Å | C/G=16-117 |
| 9D3L | EM | 2.8 Å | C/G=15-118 |
| 9D3Q | EM | 2.8 Å | C/G=13-107 |
| 9D3T | EM | 2.8 Å | C/G=16-118 |
| 9GMR | EM | 2.8 Å | C/G=2-130 |
| 9D3M | EM | 2.9 Å | C/G=16-118 |
| 9D3N | EM | 3.0 Å | C=17-107, G=19-109 |
| 9D3O | EM | 3.0 Å | C/G=12-120 |
| 6SEG | EM | 3.1 Å | C/G=1-130 |
| 9D3S | EM | 3.1 Å | C/G=15-119 |
| 9D3R | EM | 3.3 Å | C/G=16-119 |
| 6SE6 | EM | 3.5 Å | C/G=1-130 |
| 9GMK | EM | 3.5 Å | C/G=2-130 |
| 6SEF | EM | 3.7 Å | C/G=1-130 |
| 6SE0 | EM | 3.8 Å | C=2-130, G=1-130 |
| 7JZV | EM | 3.9 Å | N/n=2-130 |
| 6Y5D | EM | 4.1 Å | C/G/O/S=1-130 |
| 6SEE | EM | 4.2 Å | C/G=1-130 |
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