Cra-controlled antisense RNA-downregulation of isocitrate dehydrogenase in Escherichia coli
Bibliographic record
Abstract
Abstract In E. coli, catabolite repressor activator (Cra) protein (formerly called FruR) is known to regulate the expression of many genes positively and negatively; this effect is modulated by intracellular levels of fructose-1-phosphate (F-1-P) and fructose-1,6-bisphopahate (F-1,6-bisP). In this paper, we report conditionally expressed antisense RNA corresponding to 101bp of isocitrate dehydrogenase (icd) gene (as-icd) under Cra (FruR) responsive promoter fruB (PfruB as-icd construct denoted as pVS2K3) in E. coli K-12 (DH5α) and E. coli B (BL21) strains. Previously studies have shown that ICDH mutants failed to grow on glucose in absence of glutamate and accumulated citrate intracellularly. Hence, a conditional downregulation of icd gene could overcome this lethality and also help in understanding the flux towards citrate accumulation. Effect of PfruB as-icd (pVS2k3) construct was monitored in E. coli K-12 (DH5α) and E. coli B (BL21) during growth on carbon sources wherein the fruB promoter is active (glucose) or repressed (glycerol). A 3–4 fold decrease in ICDH activity was observed in E. coli DH5α expressing pVS2K3 on glucose but PfruB as-icd expression differed in E. coli BL21 on glucose. This alteration could be attributed to the anomalous Cra regulation seen in E. coli B strain which could be a crucial factor while choosing fruB promoter for expression studies.
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 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.001 |
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".