The SapB morphogen is a lantibiotic-like peptide derived from the product of the developmental gene <i>ramS</i> in <i>Streptomyces coelicolor</i>
Bibliographic record
Abstract
SapB is a morphogenetic peptide that is important for aerial mycelium formation by the filamentous bacterium Streptomyces coelicolor. Production of SapB commences during aerial mycelium formation and depends on most of the genes known to be required for the morphogenesis of aerial hyphae. Furthermore, the application of purified SapB to mutants blocked in morphogenesis restores their capacity to form aerial hyphae. Here, we present evidence that SapB is a lantibiotic-like peptide that is derived by posttranslational modification from the product of a gene (ramS) in the four-gene ram operon, which is under the control of the regulatory gene ramR. We show that the product of another gene in the operon (ramC) contains a region that is similar to enzymes involved in the biosynthesis of lantibiotics, suggesting that it might be involved in the posttranslational processing of RamS. We conclude that SapB is derived from RamS through proteolytic cleavage and the introduction of four dehydroalanine residues and two lanthionine bridges. We provide an example of a morphogenetic role for an antibiotic-like molecule.
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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".