Use of degenerate primers and touchdown PCR to amplify a halogenase gene fragment from Streptomyces venezuelae ISP5230
Bibliographic record
Abstract
Consensus amino acid sequences of FADH(2)-dependent bacterial halogenases were used to design PCR primers amplifying a halogenase gene fragment from the chloramphenicol producer Streptomyces venezuelae ISP5230. The sequence-specific degenerate primers (MPF1 and MPR2) were used with a touchdown PCR procedure in the first PCR-assisted cloning of a halogenase gene fragment. In the region of the 290-bp PCR product containing the reverse primer, the deduced amino acid sequence exhibited characteristics of a beta-alpha-beta fold present in FAD-binding sites of certain monooxygenases. When used to probe Southern blots of restriction-enzyme-digested DNA, the [alpha-(32)P]dCTP-labeled PCR product hybridized specifically with DNA fragments from genomic DNA of S. venezuelae ISP5230. Primers MPF1 and MPR2 also allowed amplification by PCR of approximately 290-bp DNA fragments from several other streptomycetes. The fragments from Streptomyces aureofaciens NRRL2209 and Streptomyces coelicolor A3(2) showed sequence identity with halogenase genes from these species. Thus, the PCR primers are of potential value for amplification and subsequent isolation of actinomycete halogenase genes.
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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 | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| 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".