Serine/threonine-protein phosphatase 2A activator (PTPA) is a 358-residue protein from Homo sapiens. This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: Q15257.
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The mean pLDDT of this model is 87.2 (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 | 77% |
| 70 to 90 | Confident: backbone generally right | 6% |
| 50 to 70 | Low: treat with caution | 2% |
| Below 50 | Very low: often disordered regions | 15% |
What pLDDT means and how to read it
PPIases accelerate the folding of proteins. It catalyzes the cis-trans isomerization of proline imidic peptide bonds in oligopeptides (By similarity). Acts as a regulatory subunit for serine/threonine-protein phosphatase 2A (PP2A) (PubMed:16916641, PubMed:36073231). Modulates PP2A activity or substrate specificity, probably by inducing a conformational change in the catalytic subunit, a proposed direct target of the PPIase (PubMed:16916641). Can reactivate inactive phosphatase PP2A-phosphatase methylesterase complexes (PP2A(i)) in presence of ATP and Mg(2+) (By similarity). Reversibly stimulates the variable phosphotyrosyl phosphatase activity of PP2A core heterodimer PP2A(D) in presence…
Associates with PP2A heterodimeric core enzyme PP2A(D), composed of a 36 kDa catalytic subunit (subunit C) and a 65 kDa constant regulatory subunit (PR65 or subunit A) (PubMed:16916641). Interacts with the catalytic subunit PPP2CA (via C-terminus) (PubMed:25003389). Interacts with PPP2CB (By similarity)
Cytoplasm, Nucleus
Compare the prediction with experimentally determined structures of the same protein:
| PDB ID | Method | Resolution | Chains and residues |
|---|---|---|---|
| 2IXM | X-ray | 1.5 Å | A=20-357 |
| 2G62 | X-ray | 1.6 Å | A=22-358 |
| 4NY3 | X-ray | 1.8 Å | A/B=22-358 |
| 2HV6 | X-ray | 1.9 Å | A/B=1-358 |
| 2HV7 | X-ray | 2.5 Å | A/B/C/D/E/F/G/H=1-358 |
| 4LAC | X-ray | 2.82 Å | B=19-358 |
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