RyhB small RNA modulates the free intracellular iron pool and is essential for normal growth during iron limitation in <i>Escherichia coli</i>
Bibliographic record
Abstract
The small RNA RyhB has recently been shown to negatively regulate a number of mRNAs encoding dispensable iron-using proteins in Escherichia coli. The resulting decrease in the synthesis of iron-using proteins is thought to spare iron in order to ensure its availability for iron-requiring proteins that are indispensable. Indeed, the expression of RyhB from a heterologous promoter activates the iron-sensing repressor Fur, which suggests an increase in the pool of free intracellular iron (iron-sparing). In accordance with these observations, we report here that RyhB expression increases the concentration of free intracellular iron, as shown by direct measurements of the metal in whole cells by electron paramagnetic resonance spectroscopy. Our data also suggest that iron-sparing originates from rapid uptake of extracellular iron and not from already internalized metal. Furthermore, RyhB is shown to be essential for normal bacterial growth and survival during iron starvation, which is consistent with previous data describing the function of the small RNA. Overall, our data demonstrate that, by regulating synthesis of nonessential iron-using proteins, the small RNA RyhB ensures that the iron is directed towards the iron-requiring enzymes that are indispensable.
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 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 | 0.000 |
| 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".