Protective antigen (pagA) is a 764-residue protein from Bacillus anthracis. This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: P13423.
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The mean pLDDT of this model is 88.9 (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 | 79% |
| 70 to 90 | Confident: backbone generally right | 11% |
| 50 to 70 | Low: treat with caution | 2% |
| Below 50 | Very low: often disordered regions | 8% |
What pLDDT means and how to read it
Protective antigen constitutes one of the three proteins composing the anthrax toxin; it mediates attachment to host cells and translocation of edema factor (EF) and lethal factor (LF) into the host cytoplasm (PubMed:11700562, PubMed:14507921, PubMed:15243628, PubMed:15326297). PA associated with LF forms the lethal toxin (LeTx) and causes death when injected; PA associated with EF forms the edema toxin (EdTx) and produces edema (PubMed:1651334). PA induces immunity to infection with anthrax (PubMed:11544370)
Interacts with host ANTXR1 and ANTXR2
Secreted, Host cell membrane, Host endosome membrane
Compare the prediction with experimentally determined structures of the same protein:
| PDB ID | Method | Resolution | Chains and residues |
|---|---|---|---|
| 3TEW | X-ray | 1.45 Å | A=30-764 |
| 4H2A | X-ray | 1.62 Å | A=30-764 |
| 3MHZ | X-ray | 1.7 Å | A=30-764 |
| 3TEX | X-ray | 1.7 Å | A=30-764 |
| 4NAM | X-ray | 1.7 Å | A=30-764 |
| 3TEZ | X-ray | 1.83 Å | A=30-764 |
| 4EE2 | X-ray | 1.91 Å | A=30-764 |
| 5FR3 | X-ray | 1.94 Å | A=43-764 |
| 3INO | X-ray | 1.95 Å | A/B=624-764 |
| 3Q8B | X-ray | 2.0 Å | A=30-764 |
| 1ACC | X-ray | 2.1 Å | A=30-764 |
| 3Q8E | X-ray | 2.1 Å | A=30-764 |
| 3Q8F | X-ray | 2.1 Å | A=30-764 |
| 3TEY | X-ray | 2.12 Å | A=30-764 |
| 1T6B | X-ray | 2.5 Å | X=30-764 |
| 3Q8C | X-ray | 2.85 Å | A=30-764 |
| 3J9C | EM | 2.9 Å | A=203-764 |
| 3KWV | X-ray | 3.1 Å | A/B/D/E=197-764 |
| 3Q8A | X-ray | 3.13 Å | A=30-764 |
| 6UZB | EM | 3.2 Å | A/B/C/D/E/F/G=30-764 |
Showing 20 of 34 experimental structures (best resolution first).
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