The product of the bacteriophage lambda <i>W</i> gene: purification and properties
Bibliographic record
Abstract
Gene W is one of the 10 genes that control the morphogenesis of the bacteriophage lambda head. The morpho genesis of the phage lambda head proceeds through the synthesis of an intermediate assembly called the prohead. This is an empty shell into which the bacteriophage DNA is introduced--packaged--by the phage enzyme DNA terminase. The product of W (gpW) acts after DNA packaging, but before the addition of another phage product, gene product FII, and before the addition of tails. The role of gpW is unknown. The structure of N- and C-tagged gpW has been previously determined by nuclear magnetic resonance (NMR) spectroscopy. Here we report some of the properties of the native protein. The purification of gpW to homogeneity, overproduced by a plasmid derivative, is described. To obtain large amounts of the protein, the ribosome-binding site had to be modified, showing that inefficient translation of the message is the main mechanism limiting W gene expression. The molecular weight of the protein is in close agreement to the value predicted from the DNA sequence of the gene, which suggests that it is not post-transcriptionally modified. It behaves as a monomer in solution. Radioactively labeled gpW is incorporated into phage particles in in vitro complementation, showing that gpW is a structural protein. The stage at which gpW functions and other circumstantial evidence support the idea that six molecules of gpW polymerize on the connector before the incorporation of six molecules of gpFII and before the tail attaches.
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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) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.003 |
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".