Crystallisation and initial characterization of the periplasmic domain of TraG, the conjugative entry exclusion protein from the F-plasmid
Bibliographic record
Abstract
Type IV Secretion Systems (T4SS) are a significant contributor to bacterial evolution and the emergence of antibiotic resistance as they have the unique ability of transmitting mobile DNA elements through bacterial conjugation.The F-plasmid of E. coli is representative of conjugative T4SSs found in other clinically relevant gram negative pathogens including Shigella sp., Salmonella sp., Helicobacter pylori etc. TraG is one of the largest proteins expressed from the Fplasmid and plays several roles in the conjugative process.The membrane bound N-terminal domain of TraG is involved in F-pilus synthesis, while the C-terminal periplasmic domain, denoted TraG*, is responsible for entry exclusion (Eex) and mating pair stabilization (Mps).Redundant Fplasmid transfer is prevented by Eex, which occurs when TraG in the donor cell interacts with a cognate TraS in the inner membrane of the recipient cell.Should the TraG-TraS interaction not occur, TraG then interacts with TraN within the outer membrane of donor cell to facilitate Mps; the periplasmic TraG* plays a dynamic role in the Eex/Mps checkpoint of F-mediated conjugative DNA transfer.We have recently crystallized TraG*, and present an initial characterization of the protein.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| 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 | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 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 itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".