Tol-Pal system protein TolA (tolA) is a 421-residue protein from Escherichia coli (strain K12). This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: P19934.
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The mean pLDDT of this model is 76.1 (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 | 36% |
| 70 to 90 | Confident: backbone generally right | 29% |
| 50 to 70 | Low: treat with caution | 24% |
| Below 50 | Very low: often disordered regions | 12% |
What pLDDT means and how to read it
Part of the Tol-Pal system, which plays a role in outer membrane invagination during cell division and is important for maintaining outer membrane integrity (PubMed:11115123, PubMed:11994151, PubMed:1683466, PubMed:17233825, PubMed:8416897). The Tol-Pal system is also required for polar localization of chemoreceptors clusters (PubMed:24720726). The system also appears to be required for the activity of several outer membrane-localized enzymes with cell wall remodeling activity (PubMed:32152098). Is involved in the uptake of group A colicins (colicins A, E1, E2, E3, and K) and in the uptake of filamentous phage DNA (PubMed:1683466)
The Tol-Pal system is composed of five core proteins: the inner membrane proteins TolA, TolQ and TolR, the periplasmic protein TolB and the outer membrane protein Pal. They form a network linking the inner and outer membranes and the peptidoglycan layer (PubMed:17233825). TolA interacts with TolQ and TolR via its N-terminal domain (PubMed:10419942, PubMed:7744737). Interacts with CpoB, and with…
Cell inner membrane
Compare the prediction with experimentally determined structures of the same protein:
| PDB ID | Method | Resolution | Chains and residues |
|---|---|---|---|
| 1TOL | X-ray | 1.85 Å | A=294-421 |
| 3QDP | X-ray | 2.15 Å | A=302-421 |
| 3QDR | X-ray | 2.65 Å | A=302-421 |
| 9DDM | EM | 2.94 Å | F/G=2-421 |
| 9DDN | EM | 3.18 Å | F/G=2-421 |
| 9KPZ | EM | 3.18 Å | H/I/J/K/L=2-421 |
| 9QUQ | EM | 3.28 Å | H=1-421 |
| 9QVD | EM | 3.52 Å | H/I/J=1-421 |
| 9K49 | EM | 3.6 Å | H=1-421 |
| 9KQ0 | EM | 3.6 Å | H/I/J/K/L=2-421 |
| 9KCH | EM | 4.19 Å | H=1-421 |
| 1S62 | NMR | A=325-421 |
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