Alpha-hemolysin (hly) is a 319-residue protein from Staphylococcus aureus. This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: P09616.
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The mean pLDDT of this model is 83.8 (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 | 65% |
| 70 to 90 | Confident: backbone generally right | 18% |
| 50 to 70 | Low: treat with caution | 5% |
| Below 50 | Very low: often disordered regions | 13% |
What pLDDT means and how to read it
Alpha-toxin binds to the membrane of eukaryotic cells (particularly red blood cells, RBC) forming pores, resulting in hemolysis, with the release of low-molecular weight molecules leading to eventual osmotic RBC lysis (PubMed:1587866, PubMed:20624979). Human RBCs bind much less alpha-toxin than do rabbit RBCs (PubMed:1587866, PubMed:20624979). Heptamer oligomerization and pore formation is required for lytic activity (PubMed:1587866, PubMed:20624979)
Self-assembles to first form a non-lytic oligomeric intermediate, and then, a mushroom-shaped homoheptamer structure of 100 Angstroms in length and up to 100 Angstroms in diameter (Probable) (PubMed:8943190). Interacts with human ADAM10; this interaction is required for toxin pore formation, disruption of focal adhesions, and hly-mediated cytotoxicity (PubMed:20624979)
Secreted
Compare the prediction with experimentally determined structures of the same protein:
| PDB ID | Method | Resolution | Chains and residues |
|---|---|---|---|
| 7AHL | X-ray | 1.89 Å | A/B/C/D/E/F/G=27-319 |
| 3M4D | X-ray | 1.9 Å | A/B/C/D/E/F/G=27-319 |
| 3M2L | X-ray | 2.1 Å | A/B/C/D/E/F/G=27-319 |
| 3M3R | X-ray | 2.2 Å | A/B/C/D/E/F/G=27-319 |
| 8JX2 | EM | 2.2 Å | A/B/C/D/E/F/G/H/I/J/K/L/M/N=27-319 |
| 8JX3 | EM | 2.2 Å | A/B/C/D/E/F/G/H/I/J/K/L/M/N=27-319 |
| 3M4E | X-ray | 2.3 Å | A/B/C/D/E/F/G=27-319 |
| 6U49 | X-ray | 2.35 Å | A/B/C/D/E/F/G=27-319 |
| 6U4P | X-ray | 2.49 Å | A/B/C/D/E/F/G=27-319 |
| 6U3T | X-ray | 2.79 Å | A/B=27-319 |
| 4YHD | X-ray | 2.8 Å | A/B/C/D/E/G=27-319 |
| 9M4P | EM | 3.1 Å | A/B/C/D/E/F/G=27-319 |
| 9UFA | EM | 3.1 Å | A/B/C/D/E/F/G=27-319 |
| 4IDJ | X-ray | 3.36 Å | A=27-319 |
| 7O1Q | EM | 3.4 Å | A/B/C/D/E/F/G=27-131, A/B/C/D/E/F/G=174-319 |
| 9M4A | EM | 3.46 Å | A/B/C/D/E/F/G=27-319 |
| 9MBX | EM | 3.8 Å | A/B/C/D/E/F/G=27-319 |
| 9VFW | EM | 3.8 Å | A/B/C/D/E/F/G=27-319 |
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