| Determination of (p)ppGpp Levels During Stringent Response in Streptomyces coelicolor by Thin Layer Chromatography
|
|
Author:
Date:
2016-11-05
[Abstract] The stringent response in bacteria is a stress response that is mediated by the signaling molecules guanosine tetraphosphate and pentaphosphate [(p)ppGpp], alarmones that are also directly related to virulence. Therefore, determination of (p)ppGpp levels is crucial for studying the stringent response. The protocol here outlines in a step-wise manner the detection of (p)ppGpp in the bacterium Streptomyces coelicolor during stringent response (Strauch et al., 1991) by thin layer chromatography (TLC). In the example shown here, stringent response is induced by addition of serine hydroxamate, an inhibitor of seryl tRNA synthetase. This protocol was first published in Molecular Microbiology (Sivapragasam and Grove, 2016).
[摘要] 细菌中的严格反应是由信号分子鸟苷四磷酸和五磷酸[（p）ppGpp]介导的应激反应，它们也与毒力直接相关。因此，（p）ppGpp水平的确定对于研究严格反应至关重要。这里的方案以分步方式概述在严格反应期间细菌链霉菌（Streptomyces coelicolor）中（p）ppGpp的检测（Strauch等人，1991），通过薄层色谱（TLC）。在本文所示的实施例中，通过添加丝氨酸氧肟酸盐（丝氨酸tRNA合成酶的抑制剂）诱导严格反应。该方案首次发表于Molecular Microbiology（Sivapragasam and Grove，2016）。
[背景] 薄层色谱法用于在严格反应期间分析（p）ppGpp水平在各种细菌菌种中长时间使用，并且它是用于该目的的普遍接受的方法。然而，以前发布的协议仅仅总结了主要概念，并且确定包括该过程的每个步骤的综合协议是具有挑战性的。我们在这里提出已经优化用于研究在严格的反应的详细协议。 coelicolor 。处理 S唯一的步骤。天蓝色文化已经被鉴定，并且因此方案可以容易地适应于其他细菌物种。该方法依赖于使用并入作为强碱性阴离子交换剂的聚乙烯亚胺（PEI）的TLC板。因此，PEI是用于分离离子化合物如磷酸化核苷的选择的基质（Calderón-Flores等人，2005; Mechold等人，2013; Strauch ...
|
|
|
| In vitro Transcription (IVT) and tRNA Binding Assay
|
|
Author:
Date:
2014-09-20
[Abstract] This protocol describes the coupling of (i) “live” in vitro RNA transcription with (ii) binding by a radiolabeled, pre-formed tRNA followed by native gel electrophoresis and phosphorimager scan to visualize the complex. The necessity arose from the stable structure that one RNA forms in the absence of its interaction partner. The T-box leader RNA, a transcription control system, folds into a thermodynamically very stable stem-loop structure without the tRNA present, which makes in vitro binding interaction of both pre-formed RNAs very difficult. I therefore adjusted the binding assay to mimic the “natural” situation in the bacterial cell, where the pre-formed, stable tRNA is already present while the T-box leader RNA is actively transcribed by the RNA polymerase. The ...
[摘要] 该方案描述了（i）"活"体外RNA转录与（ii）通过放射性标记的预先形成的tRNA的结合，然后是天然凝胶电泳和磷光成像仪扫描以显现复合物的偶联。 必要性来自一种RNA在不存在其相互作用配偶体时形成的稳定结构。 T盒前导RNA，转录控制系统，折叠成热力学非常稳定的茎 - 环结构，没有tRNA存在，这使得体外结合两个预先形成的RNA的相互作用非常困难。 因此，我调整结合测定以模拟细菌细胞中的"天然"情况，其中预先形成的稳定的tRNA已经存在，而T盒前导RNA被RNA聚合酶主动转录。 方案的第一部分还描述了体外转录和tRNA的标记。
|
|
|