Sclavi B, Sullivan M, Chance M R, Brenowitz M, Woodson S A
Department of Physiology and Biophysics, Center for Synchrotron Biosciences, Albert Einstein College of Medicine of Yeshiva University, 1300 Morris Park Avenue, Bronx, NY 10461, USA.
Science. 1998 Mar 20;279(5358):1940-3. doi: 10.1126/science.279.5358.1940.
Radiolysis of water with a synchrotron x-ray beam permits the hydroxyl radical-accessible surface of an RNA to be mapped with nucleotide resolution in 10 milliseconds. Application of this method to folding of the Tetrahymena ribozyme revealed that the most stable domain of the tertiary structure, P4-P6, formed cooperatively within 3 seconds. Exterior helices became protected from hydroxyl radicals in 10 seconds, whereas the catalytic center required minutes to be completely folded. The results show that rapid collapse to a partially disordered state is followed by a slow search for the active structure.
用同步加速器X射线束对水进行辐射分解，可在10毫秒内以核苷酸分辨率绘制RNA的羟基自由基可及表面。将该方法应用于嗜热四膜虫核酶的折叠过程，结果显示三级结构中最稳定的结构域P4 - P6在3秒内协同形成。外部螺旋在10秒内开始受到羟基自由基的保护，而催化中心则需要数分钟才能完全折叠。结果表明，快速折叠成部分无序状态之后是对活性结构的缓慢搜寻。
