The <i>Pseudomonas aeruginosa</i> multidrug efflux regulator MexR uses an oxidation-sensing mechanism
Bibliographic record
Abstract
MexR is a MarR family protein that negatively regulates multidrug efflux systems in the human pathogen Pseudomonas aeruginosa. The mechanism of MexR-regulated antibiotic resistance has never been elucidated in the past. We present here that two Cys residues in MexR are redox-active. They form intermonomer disulfide bonds in MexR dimer with a redox potential of -155 mV. This MexR oxidation leads to its dissociation from promoter DNA, derepression of the mexAB-oprM drug efflux operon, and increased antibiotic resistance of P. aeruginosa. We show computationally that the formation of disulfide bonds is consistent with a conformation change that prevents the oxidized MexR from binding to DNA. Collectively, the results reveal that MexR is a redox regulator that senses peroxide stress to mediate antibiotic resistance in P. aeruginosa.
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How this classification was reachedexpand
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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 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 itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, 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".