Biochemical Activities of the <i>absA</i> Two-Component System of <i>Streptomyces coelicolor</i>
Bibliographic record
Abstract
The AbsA1 sensor kinase and its cognate response regulator AbsA2 are important regulators of antibiotic synthesis in Streptomyces coelicolor. While certain point mutations in absA1 reduce or eliminate the synthesis of several antibiotics, null mutations in these genes bring about enhanced antibiotic synthesis. We show here that AbsA1, which is unusual in sequence and structure, is both an AbsA2 kinase and an AbsA2 approximately P phosphatase. The half-life of AbsA2 approximately P in solution is 68.6 min, consistent with a role in maintaining a relatively stable state of transcriptional repression or activation. We find that mutations in the absA locus that enhance antibiotic synthesis impair AbsA2 kinase activity and that mutations that repress antibiotic synthesis impair AbsA2 approximately P phosphatase activity. These results support a model in which the phosphorylation state of AbsA2 is determined by the balance of the kinase and phosphatase activities of AbsA1 and where AbsA2 approximately P represses antibiotic biosynthetic genes either directly or indirectly.
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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".