Characterization of the PilN, PilO and PilP type IVa pilus subcomplex
Why this work is in the frame
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Bibliographic record
Abstract
Type IVa pili are bacterial nanomachines required for colonization of surfaces, but little is known about the organization of proteins in this system. The Pseudomonas aeruginosa pilMNOPQ operon encodes five key members of the transenvelope complex facilitating pilus function. While PilQ forms the outer membrane secretin pore, the functions of the inner membrane-associated proteins PilM/N/O/P are less well defined. Structural characterization of a stable C-terminal fragment of PilP (PilP(Δ71)) by NMR revealed a modified β-sandwich fold, similar to that of Neisseria meningitidis PilP, although complementation experiments showed that the two proteins are not interchangeable likely due to divergent surface properties. PilP is an inner membrane putative lipoprotein, but mutagenesis of the putative lipobox had no effect on the localization and function of PilP. A larger fragment, PilP(Δ18-6His), co-purified with a PilN(Δ44)/PilO(Δ51) heterodimer as a stable complex that eluted from a size exclusion chromatography column as a single peak with a molecular weight equivalent to two heterotrimers with 1:1:1 stoichiometry. Although PilO forms both homodimers and PilN-PilO heterodimers, PilP(Δ18-6His) did not interact stably with PilO(Δ51) alone. Together these data demonstrate that PilN/PilO/PilP interact directly to form a stable heterotrimeric complex, explaining the dispensability of PilP's lipid anchor for localization and function.
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Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it