Dependence of RelA-Mediated (p)ppGpp Formation on tRNA Identity
Bibliographic record
Abstract
The bacterial stringent response is a cellular response to amino acid limitations and is characterized by the accumulation of the alarmone polyphosphate guanosine ((p)ppGpp). A key molecular event leading to (p)ppGpp synthesis is the binding of a deacylated tRNA to the vacant A-Site of a ribosome. The resulting ribosomal complex is recognized by and activates RelA, the (p)ppGpp synthetase. Activated RelA catalyzes (p)ppGpp formation until the deacylated tRNA passively dissociates from the ribosomal A-Site. In this report, we have investigated a novel role for the identity of A-Site bound tRNA in RelA-mediated (p)ppGpp synthesis. A comparison in the stimulation of RelA activity was made using ribosome complexes with either a tightly or weakly binding deacylated tRNA occupying the A-Site. In vitro analysis reveals that ribosome complexes formed with tight binding tRNA(Val) stimulate RelA activity at lower concentrations than that required for ribosome complexes formed with the weaker binding tRNA(Phe). The data suggest that the recovery from the stringent response may be dependent on the identity of the amino acid that was initially limiting for the bacteria.
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 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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".