Genetic analysis of the<i>Salmonella</i>transcription factor HilA
Bibliographic record
Abstract
HilA, a Salmonella transcription factor, activates the invF-1 and prgH promoters through binding to the HilA box, which contains 2 copies of a TTKHAT motif separated by a T centered at -45 relative to the start sites of transcription. The N-terminal 112 amino acids of HilA are similar to winged helix-turn-helix DNA binding/transcription activation domains (wHTH DBDs). The remaining 441 amino acids are not similar in sequence to any other well-characterized transcription factors. Here, we report that the wHTH DBD is essential for activation of both promoters, but amino acids 113-554 are only required for normal activation of invF-1. Some alanine substitutions in the putative alpha loop, which connects the recognition and positioning helices in wHTH DBDs, cause a loss-of-activation phenotype. A hilA allele encoding a protein with an alanine substituted for arginine at position 71 in the alpha loop has a loss-of-activation defect exclusively at the prgH promoter. The results suggest distinct roles for one or more domains formed by amino acids 113-554 and for arginine 71 in activation of the 2 promoters.
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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 | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.001 |
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".