Woodson S A
T. C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, Maryland 21218-2685, USA.
Cell Mol Life Sci. 2000 May;57(5):796-808. doi: 10.1007/s000180050042.
Methods for probing RNA structure in real time have revealed that initial folding steps are complete in less than a second. Refolding of large catalytic RNAs in vitro often results in long-lived intermediates that reach the native structure very slowly. These kinetically trapped intermediates arise from alternative secondary structures that form early in the folding process. In cells, proteins modulate the outcome of RNA folding reactions by stabilizing specific conformations or by accelerating refolding of misfolded intermediates. At the same time, competition between metastable conformations provides a means for regulating the biological activity of transcripts.
实时探测RNA结构的方法表明，最初的折叠步骤在不到一秒的时间内就完成了。体外大催化RNA的重新折叠通常会产生寿命很长的中间体，这些中间体达到天然结构的速度非常缓慢。这些动力学上被困住的中间体源于折叠过程早期形成的替代二级结构。在细胞中，蛋白质通过稳定特定构象或加速错误折叠中间体的重新折叠来调节RNA折叠反应的结果。与此同时，亚稳态构象之间的竞争为调节转录本的生物活性提供了一种手段。
