Tuning RNA Flexibility with Helix Length and Junction Sequence.
Tuning RNA Flexibility with Helix Length and Junction Sequence.
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DOI：
10.1016/j.bpj.2015.10.039
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发表时间：
2015-12
影响因子：
3.4
通讯作者：
Julie L. Sutton;L. Pollack
中科院分区：
文献类型：
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作者：
Julie L. Sutton;L. Pollack
随着人们对RNA在生物学中的核心作用的认识不断提高，人们需要对RNA如何像蛋白质一样识别生物伴侣有一个新的认识。由于RNA具有固有的灵活性，因此它呈现出各种构象。这种构象灵活性可能是RNA如何吸引和结合分子伴侣的关键方面。在结构上，RNA由刚性碱基配对的双链体组成，由柔性非碱基配对区域隔开。在这里，使用由两个短螺旋组成的RNA系统，由单链（非碱基配对）连接，我们探讨了螺旋长度和连接序列在确定模型RNA的构象范围中的作用。单分子Förster共振能量转移报告RNA构象作为一价或二价离子浓度的函数。在低盐浓度下，螺旋之间的静电排斥占主导地位，而在高盐浓度下，连接序列效应决定构象。在生理盐浓度附近，RNA构象对螺旋长度和连接序列都很敏感，这表明了一种灵敏地调节RNA构象的方法。
The increasing awareness of RNA's central role in biology calls for a new understanding of how RNAs, like proteins, recognize biological partners. Because RNA is inherently flexible, it assumes a variety of conformations. This conformational flexibility can be a critical aspect of how RNA attracts and binds molecular partners. Structurally, RNA consists of rigid basepaired duplexes, separated by flexible non-basepaired regions. Here, using an RNA system consisting of two short helices, connected by a single-stranded (non-basepaired) junction, we explore the role of helix length and junction sequence in determining the range of conformations available to a model RNA. Single-molecule Förster resonance energy transfer reports on the RNA conformation as a function of either mono- or divalent ion concentration. Electrostatic repulsion between helices dominates at low salt concentration, whereas junction sequence effects determine the conformations at high salt concentration. Near physiological salt concentrations, RNA conformation is sensitive to both helix length and junction sequence, suggesting a means for sensitively tuning RNA conformations.