Ionic strength-dependent persistence lengths of single-stranded RNA and DNA
Ionic strength-dependent persistence lengths of single-stranded RNA and DNA
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DOI：
10.1073/pnas.1119057109
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发表时间：
2012-01-17
影响因子：
11.1
通讯作者：
Pollack, Lois
中科院分区：
文献类型：
--
作者：
Chen, Huimin;Meisburger, Steve P.;Pollack, Lois
动态RNA分子在细胞中进行基本过程，包括翻译和剪接。碱基对相互作用使RNA稳定为相对刚性的结构，而柔性的非碱基配对区域允许RNA经历功能所需的构象变化。为了提高我们对RNA折叠和动力学的理解，了解这些非碱基配对区域的灵活性以及它如何依赖于抗衡离子是至关重要的。然而，关于核酸聚合物性质的信息主要来自ssDNA的研究。在这里，我们测量ssRNA的持续长度（l（p））。我们在使用SAXS和smFRET的强大组合测量的脱氧胸苷酸（dT（40））和尿苷酸（rU（40））的40聚体之间的直接比较中观察到l（p）的价和离子强度依赖性差异。我们还表明，核酸的灵活性是受当地环境（相邻的双螺旋）。我们的研究结果说明了复杂的构象和离子环境之间的相互作用，调节核酸在体内的功能。
Dynamic RNA molecules carry out essential processes in the cell including translation and splicing. Base-pair interactions stabilize RNA into relatively rigid structures, while flexible non-base-paired regions allow RNA to undergo conformational changes required for function. To advance our understanding of RNA folding and dynamics it is critical to know the flexibility of these un-base-paired regions and how it depends on counterions. Yet, information about nucleic acid polymer properties is mainly derived from studies of ssDNA. Here we measure the persistence lengths (l(p)) of ssRNA. We observe valence and ionic strength-dependent differences in l(p) in a direct comparison between 40-mers of deoxythymidylate (dT(40)) and uridylate (rU(40)) measured using the powerful combination of SAXS and smFRET. We also show that nucleic acid flexibility is influenced by local environment (an adjoining double helix). Our results illustrate the complex interplay between conformation and ion environment that modulates nucleic acid function in vivo.