Cyclin-dependent kinase inhibitor 1 (CDKN1A) is a 164-residue protein from Homo sapiens. This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: P38936.
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The mean pLDDT of this model is 69.0 (low 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 | 28% |
| 70 to 90 | Confident: backbone generally right | 17% |
| 50 to 70 | Low: treat with caution | 30% |
| Below 50 | Very low: often disordered regions | 25% |
What pLDDT means and how to read it
Plays an important role in controlling cell cycle progression and DNA damage-induced G2 arrest (PubMed:9106657). Involved in p53/TP53 mediated inhibition of cellular proliferation in response to DNA damage. Also involved in p53-independent DNA damage-induced G2 arrest mediated by CREB3L1 in astrocytes and osteoblasts (By similarity). Binds to and inhibits cyclin-dependent kinase activity, preventing phosphorylation of critical cyclin-dependent kinase substrates and blocking cell cycle progression. Functions in the nuclear localization and assembly of cyclin D-CDK4 complex and promotes its kinase activity towards RB1. At higher stoichiometric ratios, inhibits the kinase activity of the…
Interacts with HDAC1; the interaction is prevented by competitive binding of C10orf90/FATS to HDAC1 facilitating acetylation and protein stabilization of CDKN1A/p21 (By similarity). Interacts with MKRN1 (PubMed:19536131). Interacts with PSMA3 (PubMed:11350925). Interacts with PCNA (PubMed:11595739, PubMed:18703516, PubMed:18794347, PubMed:8861913). Component of the ternary complex, cyclin…
Cytoplasm, Nucleus
Compare the prediction with experimentally determined structures of the same protein:
| PDB ID | Method | Resolution | Chains and residues |
|---|---|---|---|
| 5E0U | X-ray | 1.93 Å | D/E/F=139-160 |
| 2ZVV | X-ray | 2.0 Å | X/Y=139-160 |
| 8GJF | X-ray | 2.0 Å | D/E/F=141-155 |
| 4RJF | X-ray | 2.01 Å | B/D/F=139-160 |
| 7KQ0 | X-ray | 2.4 Å | B/D/F=141-155 |
| 2ZVW | X-ray | 2.5 Å | I/J/K/L/M/N/O/P=139-160 |
| 1AXC | X-ray | 2.6 Å | B/D/F=139-160 |
| 6CBI | X-ray | 2.75 Å | H/I/J/K=139-152 |
| 6P8H | X-ray | 3.19 Å | C=9-85 |
| 7KQ1 | X-ray | 3.3 Å | B/D/F=141-155 |
| 6CEJ | NMR | A=139-152 | |
| 6CIV | NMR | C=139-152 | |
| 6CIX | NMR | B=139-152 |
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