Surface presentation of antigens protein SpaK (spaK) is a 135-residue protein from Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720). This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: P0A1N0.
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The mean pLDDT of this model is 92.3 (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 | 80% |
| 70 to 90 | Confident: backbone generally right | 18% |
| 50 to 70 | Low: treat with caution | 2% |
| Below 50 | Very low: often disordered regions | 0% |
What pLDDT means and how to read it
Involved in a secretory pathway responsible for the surface presentation of determinants needed for the entry of Salmonella species into mammalian cells. Chaperone specialized in the storage of effectors within the bacterial cytoplasm, maintaining them in a secretion-competent state, and allowing their immediate delivery to target cells upon contact of the bacterium with the host cells. Has been shown to chaperone SopA, SopE, SopE2 and SipA
Homodimer
Compare the prediction with experimentally determined structures of the same protein:
| PDB ID | Method | Resolution | Chains and residues |
|---|---|---|---|
| 2FM8 | X-ray | 2.2 Å | A/B=1-134 |
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