Tan Zhi-Jie, Chen Shi-Jie
Department of Physics and Key Laboratory of Artificial Micro- and Nano-Structures of the Ministry of Education, School of Physics and Technology, Wuhan University, Wuhan 430 072, China.
Met Ions Life Sci. 2011;9:101-24.
RNAs are highly charged polyanionic molecules. RNA structure and function are strongly correlated with the ionic condition of the solution. The primary focus of this article is on the role of diffusive ions in RNA folding. Due to the long-range nature of electrostatic interactions, the diffuse ions can contribute significantly to RNA structural stability and folding kinetics. We present an overview of the experimental findings as well as the theoretical developments on the diffuse ion effects in RNA folding. This review places heavy emphasis on the effect of magnesium ions. Magnesium ions play a highly efficient role in stabilizing RNA tertiary structures and promoting tertiary structural folding. The highly efficient role goes beyond the mean-field effect such as the ionic strength. In addition to the effects of specific ion binding and ion dehydration, ion-ion correlation for the diffuse ions can contribute to the efficient role of the multivalent ions such as the magnesium ions in RNA folding.
RNA是高度带电的聚阴离子分子。RNA的结构和功能与溶液的离子条件密切相关。本文的主要重点是扩散离子在RNA折叠中的作用。由于静电相互作用的长程性质，扩散离子可对RNA结构稳定性和折叠动力学做出显著贡献。我们概述了关于RNA折叠中扩散离子效应的实验发现以及理论进展。本综述着重强调了镁离子的作用。镁离子在稳定RNA三级结构和促进三级结构折叠方面发挥着高效作用。这种高效作用超越了诸如离子强度等平均场效应。除了特定离子结合和离子脱水的影响外，扩散离子的离子-离子相关性可有助于多价离子如镁离子在RNA折叠中的高效作用。
