Adhya S, Gottesman M, De Crombrugghe B
Proc Natl Acad Sci U S A. 1974 Jun;71(6):2534-8. doi: 10.1073/pnas.71.6.2534.
The induction of lambda prophage provokes the constitutive expression of the adjacent gal operon in E. coli. This "escape synthesis" can result from transcription that initiates at a phage promoter and extends into the gal operon. The effect requires the product of the lambda gene N. N-mediated transcription not only fails to terminate at the prophage-bacterial junction and at the ends of bacterial operons, but ignores termination signals caused by polar insertions or ochre mutations within gal. Suppression of polarity by N-function is a cis-effect; only transcription initiated at the phage promoter is influenced. We propose that the transcription complex is influenced by N-product to become termination-resistant at a site in the phage genome (juggernaut model). This site appears to be at or near the phage promoter.
λ原噬菌体的诱导会引发大肠杆菌中相邻半乳糖操纵子的组成型表达。这种“逃逸合成”可能源于在噬菌体启动子起始并延伸至半乳糖操纵子的转录。该效应需要λ基因N的产物。N介导的转录不仅不会在原噬菌体 - 细菌交界处和细菌操纵子末端终止，而且会忽略由半乳糖内的极性插入或赭石突变引起的终止信号。N功能对极性的抑制是一种顺式效应；只有在噬菌体启动子起始的转录会受到影响。我们提出转录复合物受N产物影响，在噬菌体基因组中的一个位点变得抗终止（主宰模型）。该位点似乎位于噬菌体启动子处或其附近。
