The <i>Helicobacter pylori</i> MutS protein confers protection from oxidative DNA damage
Bibliographic record
Abstract
The human gastric pathogenic bacterium Helicobacter pylori lacks a MutSLH-like DNA mismatch repair system. Here, we have investigated the functional roles of a mutS homologue found in H. pylori, and show that it plays an important physiological role in repairing oxidative DNA damage. H. pylori mutS mutants are more sensitive than wild-type cells to oxidative stress induced by agents such as H2O2, paraquat or oxygen. Exposure of mutS cells to oxidative stress results in a significant ( approximately 10-fold) elevation of mutagenesis. Strikingly, most mutations in mutS cells under oxidative stress condition are G:C to T:A transversions, a signature of 8-oxoguanine (8-oxoG). Purified H. pylori MutS protein binds with a high specific affinity to double-stranded DNA (dsDNA) containing 8-oxoG as well as to DNA Holliday junction structures, but only weakly to dsDNA containing a G:A mismatch. Under oxidative stress conditions, mutS cells accumulate higher levels (approximately threefold) of 8-oxoG DNA lesions than wild-type cells. Finally, we observe that mutS mutant cells have reduced colonization capacity in comparison to wild-type cells in a mouse infection model.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.000 | 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 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.000 | 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".