Two transcription pause elements underlie a σ70-dependent pause cycle.
Two transcription pause elements underlie a σ70-dependent pause cycle.
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两个转录暂停元件构成了依赖于 70 的暂停周期。
DOI：
10.1073/pnas.1512986112
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发表时间：
2015
影响因子：
11.1
通讯作者：
Roberts,JeffreyW
中科院分区：
文献类型：
--
作者：
Strobel,EricJ;Roberts,JeffreyW
RNA聚合酶（RNAP）在转录延伸过程中的运动受到DNA编码元件的调节，这些元件导致延伸复合物暂停。最具特征的暂停序列之一是σ 70起始因子的结合位点，其在类杆状病毒噬菌体晚期基因启动子附近的位点诱导暂停。这种σ70依赖性暂停的一个重要组成部分是元素暂停位点（EPS），该序列本身诱导整个大肠杆菌基因组的转录暂停，并成为其他复杂的调节暂停元件（如theop和his操纵子暂停）的基础。在这里，我们确定并提供了一个详细的动力学分析的转录周期类似于失败的循环，基础上的σ70依赖性暂停。我们发现，在σ70依赖暂停，元素暂停的行为主要是调节复合物试图脱离σ70：DNA相互作用的速率。我们的研究结果建立了σ70依赖的暂停编码区作为一个多部分的元素，其中几个暂停诱导组件作出不同的机械贡献的诱导和维持的调节转录暂停。
The movement of RNA polymerase (RNAP) during transcription elongation is modulated by DNA-encoded elements that cause the elongation complex to pause. One of the best-characterized pause sequences is a binding site for the σ70initiation factor that induces pausing at a site near lambdoid phage late-gene promoters. An essential component of this σ70-dependent pause is the elemental pause site (EPS), a sequence that itself induces transcription pausing throughout theEscherichia coligenome and underlies other complex regulatory pause elements, such as theopsandhisoperon pauses. Here, we identify and provide a detailed kinetic analysis of a transcription cycle analogous to abortive cycling that underlies the σ70-dependent pause. We show that, in σ70-dependent pausing, the elemental pause acts primarily to modulate the rate at which complexes attempt to disengage the σ70:DNA interaction. Our findings establish the σ70-dependent pause-encoding region as a multipartite element in which several pause-inducing components make distinct mechanistic contributions to the induction and maintenance of a regulatory transcription pause.