A wide variety of mechanisms that control gene expression in bacteria are based on conditional transcription termination. Generally, in these mechanisms, a transcription terminator is located between a promoter and a downstream gene(s), and the efficiency of the terminator is controlled by a regulatory effector that can be a metabolite, protein, or RNA. The most common type of regulation involving conditional termination is transcription attenuation, in which the primary regulatory target is an essential element of a single terminator. The terminator can be either intrinsic or Rho dependent, with each presenting unique regulatory targets. Transcription attenuation mechanisms can be divided into five classes based primarily on the manner in which transcription termination is rendered conditional. This review summarizes each class of control mechanisms from a historical perspective, describes important examples in a physiological context and the current state of knowledge, highlights major advances, and discusses expectations of future discoveries.

中文翻译：

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通过转录衰减调节细菌基因表达。

控制细菌中基因表达的多种机制均基于条件转录终止。通常，在这些机制中，转录终止子位于启动子和下游基因之间，并且终止子的效率由调节效应子控制，所述调节效应子可以是代谢产物，蛋白质或RNA。涉及条件终止的最常见调控类型是转录衰减，其中主要调控靶标是单个终止子的重要组成部分。终止子可以是固有的，也可以是Rho依赖性的，每个终止子都具有独特的调控靶标。转录衰减机制可以主要基于使转录终止成为条件的方式分为五类。