The cellular environment stabilizes adenine riboswitch RNA structure.
The cellular environment stabilizes adenine riboswitch RNA structure.
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DOI：
10.1021/bi401207q
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发表时间：
2013-12-03
期刊：
影响因子：
2.9
通讯作者：
Pielak GJ
中科院分区：
文献类型：
--
作者：
Tyrrell J;McGinnis JL;Weeks KM;Pielak GJ
细胞内环境与广泛用于体外研究RNA结构和功能的条件之间存在很大差异。为了评估拥挤的细胞环境对RNA的影响，我们研究了腺嘌呤核糖开关适体结构域的结构和配体结合功能，在健康的，生长的大肠杆菌细胞中，在单核苷酸分辨率分钟的时间尺度上使用SHAPE。配体结合的适体结构在细胞中和在1 mM Mg2+（我们在细胞中测量的近似Mg2+浓度）的缓冲液中基本相同。相比之下，无配体的适体的细胞内构象与完全折叠的配体结合状态更相似。即使向用于体外分析的缓冲液中加入高浓度的Mg2+，也没有产生细胞中游离适体所观察到的构象。因此，细胞环境比单独的Mg 2+显著更稳定适体。我们的研究结果表明，细胞内环境对RNA结构有很大的影响，最终有利于高度组织的构象。
There are large differences between the intracellular environment and the conditions widely used to study RNA structure and function in vitro. To assess the effects of the crowded cellular environment on RNA, we examined the structure and ligand-binding function of the adenine riboswitch aptamer domain in healthy, growing Escherichia coli cells at single-nucleotide resolution on the minute timescale using SHAPE. The ligand-bound aptamer structure is essentially the same in cells and in buffer at 1 mM Mg2+, the approximate Mg2+ concentration we measured in cells. In contrast, the in-cell conformation of the ligand-free aptamer is much more similar to the fully folded ligand-bound state. Even adding high Mg2+ concentrations to the buffer used for in vitro analyses did not yield the conformation observed for the free aptamer in cells. The cellular environment thus stabilizes the aptamer significantly more than does Mg2+ alone. Our results show that the intracellular environment has a large effect on RNA structure that ultimately favors highly organized conformations.