The Catalytic Mechanism of Glutamyl-tRNA Synthetase of Escherichia coli
Bibliographic record
Abstract
The sequence of substrate binding and of end-product dissociation at the steady state of the catalytic process of tRNAGlu aminoacylation by glutamyl-tRNA synthetase from Escherichia coli has been investigated using bisubstrate kinetics, dead-end and end-product inhibition studies. The nature of the kinetic patterns indicates that ATP and tRNAGlu bind randomly to the free enzyme, whereas glutamate binds only to the ternary enzyme . tRNAGlu . ATP complex. Binding of ATP to the enzyme hinders that of tRNAGlu and vice versa. After interconversion of the quaternary enzyme . substrates complex the end-products dissociate in the following order: PPi first, AMP second and Glu-tRNA last. In addition to its role as substrate and as effector with ATP for the binding of glutamate, tRNAGlu promotes the catalytically active enzyme state. Whereas at saturating tRNAGlu concentration the catalysis is rate-determining, this conformational change can be rate-determining at low tRNAGlu concentrations. The results are discussed in the light of the two-step aminoacylation pathway catalyzed by this synthetase.
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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 | 0.000 |
| 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 | 0.001 | 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".