The σ70 subunit of RNA polymerase mediates a promoter-proximal pause at the lac promoter
The σ70 subunit of RNA polymerase mediates a promoter-proximal pause at the lac promoter
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DOI：
10.1038/nsmb757
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发表时间：
2004-06-01
影响因子：
16.8
通讯作者：
Hochschild, A
中科院分区：
文献类型：
--
作者：
Nickels, BE;Mukhopadhyay, J;Hochschild, A
RNA 聚合酶的 sigma(70) 亚基在转录起始中起着重要作用。此外，sigma(70) 在噬菌体 lambda 晚期启动子 lambdaP(R) 的转录延伸过程中具有关键的调节作用。在此启动子处，sigma(70) 通过与最初转录区域中类似于启动子 10 元件的 DNA 序列元件接触，介导早期延伸的暂停。在这里，我们提供的证据表明 sigma(70) 还介导 lac 启动子 (plac) 早期延伸的暂停。与 lambdaP(R) 处的暂停一样，p lac 处的暂停是由最初转录区域中类似于启动子 10 元件的序列元件促进的。通过生物物理分析，我们证明 lac 处的暂停诱导序列元件稳定了 sigma(70) 和转录延伸复合物其余部分之间的相互作用。生物信息学分析表明，启动子近端 sigma(70) 依赖性暂停可能在许多细菌启动子的调节中发挥作用。
The sigma(70) subunit of RNA polymerase plays an essential role in transcription initiation. In addition, sigma(70) has a critical regulatory role during transcription elongation at the bacteriophage lambda late promoter, lambdaP(R). At this promoter, sigma(70) mediates a pause in early elongation through contact with a DNA sequence element in the initially transcribed region that resembles a promoter-10 element. Here we provide evidence that sigma(70) also mediates a pause in early elongation at the lac promoter (plac). Like that at lambdaP(R), the pause at p lac is facilitated by a sequence element in the initially transcribed region that resembles a promoter-10 element. Using biophysical analysis, we demonstrate that the pause-inducing sequence element at lac stabilizes the interaction between sigma(70) and the remainder of the transcription elongation complex. Bioinformatic analysis suggests that promoter-proximal sigma(70)-dependent pauses may play a role in the regulation of many bacterial promoters.