启动子阻遏：通过启动子的转录可能会抑制其活性。

Promoter occlusion: transcription through a promoter may inhibit its activity.

作者信息

Adhya S, Gottesman M

出版信息

Cell. 1982 Jul;29(3):939-44. doi: 10.1016/0092-8674(82)90456-1.

Abstract

Induction of prophage lambda inhibits the expression of the gal operon from its cognate promoters. The effect is observed only in cis, and is due to frequent transcription of the gal promoter region by RNA polymerase molecules initiating upstream at the prophage PL promoter. The frequency of transcription initiation at PL is some 30 times greater than that at the gal promoter, Pg1. PL is one of the strongest procaryotic promoters. This "promoter occlusion" is essentially complete when the distance between gal and PL is small (less than or equal to 10 kb); and when PL is fully active (that is, in the absence of the cl or cro repressors). We discuss the possibility that promoter occlusion at two lambda promoters, Pint and PR', might play a role in the sequential expression of viral functions.

摘要

原噬菌体λ的诱导抑制了半乳糖操纵子从其同源启动子的表达。这种效应仅在顺式作用中观察到，并且是由于RNA聚合酶分子从原噬菌体PL启动子上游起始，频繁转录半乳糖启动子区域所致。PL处的转录起始频率比半乳糖启动子Pg1处的转录起始频率大约高30倍。PL是最强的原核启动子之一。当半乳糖和PL之间的距离较小时（小于或等于10 kb），并且当PL完全活跃时（即，在没有cl或cro阻遏物的情况下），这种“启动子阻遏”基本完全。我们讨论了λ的两个启动子Pint和PR'处的启动子阻遏可能在病毒功能的顺序表达中起作用的可能性。