Tol-Pal system protein TolQ (tolQ) is a 230-residue protein from Escherichia coli (strain K12). This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: P0ABU9.
Explore in 3D Color by confidence AlphaFold DB UniProt
The mean pLDDT of this model is 91.8 (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 | 76% |
| 70 to 90 | Confident: backbone generally right | 18% |
| 50 to 70 | Low: treat with caution | 5% |
| Below 50 | Very low: often disordered regions | 1% |
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:1683466, PubMed:17233825). Required, with TolR, for the proton motive force-dependent activation of TolA and for TolA-Pal interaction (PubMed:11722743). 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…
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). TolQ interacts with the N-terminal domain of TolA and with TolR (PubMed:10419942, PubMed:7744737)
Cell inner membrane
Compare the prediction with experimentally determined structures of the same protein:
| PDB ID | Method | Resolution | Chains and residues |
|---|---|---|---|
| 9O40 | EM | 2.92 Å | A/B/C/D/E=1-230 |
| 9DDM | EM | 2.94 Å | A/B/C/D/E=1-230 |
| 9DDN | EM | 3.18 Å | A/B/C/D/E=1-230 |
| 9KPZ | EM | 3.18 Å | A/B/C/D/E=2-230 |
| 9QUQ | EM | 3.28 Å | A/B/C/D/E=1-230 |
| 9QVD | EM | 3.52 Å | A/B/C/D/E=1-230 |
| 9K49 | EM | 3.6 Å | A/B/C/D/E=1-230 |
| 9KQ0 | EM | 3.6 Å | A/B/C/D/E=2-230 |
| 9KCH | EM | 4.19 Å | A/B/C/D/E=1-230 |
| 8ODT | EM | 4.2 Å | A/B/C/D/E=1-230 |
MolViewer loads the AlphaFold model straight from AlphaFold DB into your browser. Show it as a cartoon, color by pLDDT, measure distances and angles, and load a PDB structure next to it to compare.