期刊
JOURNAL OF MOLECULAR BIOLOGY
卷 343, 期 5, 页码 1195-1206出版社
ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD
DOI: 10.1016/j.jmb.2004.08.080
关键词
RNA folding; electrostatic relaxation; tertiary interaction formation; compaction; P4-P6 domain
资金
- NIGMS NIH HHS [P01-GM-66275, R01-GM-52348] Funding Source: Medline
Counterions are required for RNA folding, and divalent metal ions such as Mg2+ are often critical. To dissect the role of counterions, we have compared global and local folding of wild-type and mutant variants of P4-P6 RNA derived from the Tetrahymena group I ribozyme in monovalent and in divalent metal ions. A remarkably simple picture of the folding thermodynamics emerges. The equilibrium folding pathway in monovalent ions displays two phases. In the first phase, RNA molecules that are initially in an extended conformation enforced by charge-charge repulsion are relaxed by electrostatic screening to a state with increased flexibility but without formation of long-range tertiary contacts. At higher concentrations of monovalent ions, a state that is nearly identical to the native folded state in the presence of Mg2+ is formed, with tertiary contacts that involve base and backbone interactions but without the subset of interactions that involve specific divalent metal ion-binding sites. The folding model derived from these and previous results provides a robust framework for understanding the equilibrium and kinetic folding of RNA. (C) 2004 Elsevier Ltd. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据