An optimal Mg2+ concentration for kinetic folding of the Tetrahymena ribozyme
An optimal Mg2+ concentration for kinetic folding of the Tetrahymena ribozyme
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DOI：
10.1073/pnas.96.22.12471
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发表时间：
1999-10-26
影响因子：
11.1
通讯作者：
Williamson, JR
中科院分区：
文献类型：
--
作者：
Rook, MS;Treiber, DK;Williamson, JR
Divalent metal ions, such as Mg2+, are generally required for tertiary structure formation in RNA. Although the role of Mg2+ binding in RNA-folding equilibria has been studied extensively. little is known about the role of Mg2+ in RNA-folding kinetics. In this paper, we explore the effect of Mg2+ on the rate-limiting step in the kinetic folding pathway of the Tetrahymena ribozyme. Analysis of these data reveals the presence of a Mg2+-stabilized kinetic trap that slows folding at higher Mg2+ concentrations. Thus, the Tetrahymena ribozyme folds with an optimal rate at 2 mM Mg2+, just above the concentration required for stable structure formation. These results suggest that thermodynamic and kinetic folding of RNA are cooptimized at a Mg2+ concentration that is sufficient to stabilize the folded form but low enough to avoid kinetic traps and misfolding.
