Production of bleomycin N-acetyltransferase in Escherichia coli and Streptomyces verticillus
Bibliographic record
Abstract
Bleomycin-producing Streptomyces verticillus ATCC 15003 has two bleomycin resistance genes, designated blmA and blmB. Bleomycin N-acetyltransferase, encoded by blmB, was overproduced in Escherichia coli as a protein fused to the maltose-binding protein. The protein (fBAT), purified to homogeneity after digestion of the fusion product with blood coagulation factor Xa protease, had an additional 6 N-terminal amino acid residues, but retained its bleomycin-acetylating activity, as did the entire fusion protein. The K(m) and Vmax values of purified fBAT for the substrate bleomycin were 13.0 microM and 3.4 nmol [corrected] min-1 ml-1, respectively. The optimal pH for the acetylating activity was 6.0 in 10 mM phosphate buffer. The molecular mass and pI value of fBAT were estimated by polyacrylamide gel electrophoresis to be about 34500 and 6.13, respectively. An anti-fBAT monoclonal antibody was generated and used to show that bleomycin N-acetyltransferase is expressed simultaneously with bleomycin production in S. verticillus.
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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) | 0.000 | 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 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".