A conformational switch is responsible for the reversal of the 6S RNA-dependent RNA polymerase inhibition in Escherichia coli
A conformational switch is responsible for the reversal of the 6S RNA-dependent RNA polymerase inhibition in Escherichia coli
复制标题
构象转换负责逆转大肠杆菌中 6S RNA 依赖性 RNA 聚合酶抑制
DOI：
10.1515/hsz-2012-0237
复制
发表时间：
2012
期刊：
影响因子：
3.7
通讯作者：
R. Wagner
中科院分区：
文献类型：
--
作者：
Benedikt Steuten;R. Wagner
摘要6S RNA是细菌的一种转录调节因子，它在稳定期积累，与含σ70的RNA聚合酶稳定结合，抑制许多启动子的转录。这种抑制性RNA聚合酶~6S RNA复合物在营养上调期间解离，当细胞从稳定期经历生长时，释放活性RNA聚合酶准备转录。释放反应取决于6S RNA的特征性质，即作为小RNA（称为pRNA）的从头合成的模板。在这里，我们使用结构特异性RNA酶的有限水解和分离的6S RNA和6S RNA~pRNA复合物的在线探测来研究导致释放反应的分子细节。我们的研究结果表明，pRNA转录诱导的6S RNA二级结构的重折叠，通过破坏部分的封闭茎（保守序列区CRI和CRIV）和形成一个新的发夹（保守序列区CRIII和CRIV）。在静止生长和生长过程中的活细胞中的6S RNA的硫酸二甲酯修饰模式的比较证实了在体外观察到的构象变化。基于我们的研究结果，描述的释放反应的各个步骤的模型。
Abstract 6S RNA is a bacterial transcriptional regulator, which accumulates during stationary phase and inhibits transcription from many promoters due to stable association with σ70-containing RNA polymerase. This inhibitory RNA polymerase~6S RNA complex dissociates during nutritional upshift, when cells undergo outgrowth from stationary phase, releasing active RNA polymerase ready for transcription. The release reaction depends on a characteristic property of 6S RNAs, namely to act as template for the de novo synthesis of small RNAs, termed pRNAs. Here, we used limited hydrolysis with structure-specific RNases and in-line probing of isolated 6S RNA and 6S RNA~pRNA complexes to investigate the molecular details leading to the release reaction. Our results indicate that pRNA transcription induces the refolding of the 6S RNA secondary structure by disrupting part of the closing stem (conserved sequence regions CRI and CRIV) and formation of a new hairpin (conserved sequence regions CRIII and CRIV). Comparison of the dimethylsulfate modification pattern of 6S RNA in living cells at stationary growth and during outgrowth confirmed the conformational change observed in vitro. Based on our results, a model describing the individual steps of the release reaction is presented.
影响因子：
--
作者：
Sandra E. Wells;John M. X. Hughes;A. Igel;M. Ares
通讯作者：
Sandra E. Wells;John M. X. Hughes;A. Igel;M. Ares
影响因子：
16
作者：
Goldman SR;Sharp JS;Vvedenskaya IO;Livny J;Dove SL;Nickels BE
通讯作者：
Nickels BE
DOI：
10.1073/pnas.97.13.7090
发表时间：
2000-06-20
影响因子：
11.1
作者：
Artsimovitch, I;Landick, R
通讯作者：
Landick, R