Persistence Length Changes Dramatically as RNA Folds

作     者：G. Caliskan C. Hyeon U. Perez-Salas R. M. Briber S. A. Woodson D. Thirumalai 

作者机构：T. C. Jenkins Department of Biophysics Johns Hopkins University 3400 North Charles Street Baltimore Maryland 21218 USA Center for Neutron Research National Institute of Standards and Technology Gaithersburg Maryland 20899 USA Biophysics Program Institute For Physical Science and Technology University of Maryland College Park Maryland 20742 USA Department of Physiology and Biophysics University of California at Irvine Irvine California 92697 USA Department of Materials Science and Engineering University of Maryland College Park Maryland 20742 USA 

出 版 物：《Physical Review Letters》 (Phys Rev Lett)

年 卷 期：2005年第95卷第26期

页      面：268303-268303页

核心收录：

学科分类：07[理学] 0702[理学-物理学] 

主　　题：RNA 

摘      要：We determine the persistence length lp for a bacterial group I ribozyme as a function of concentration of monovalent and divalent cations by fitting the distance distribution functions P(r) obtained from small angle x-ray scattering intensity data to the asymptotic form of the calculated PWLC(r) for a wormlike chain. The lp values change dramatically over a narrow range of Mg2+ concentration from ∼21 Å in the unfolded state (U) to ∼10 Å in the compact (IC) and native states. Variations in lp with increasing Na+ concentration are more gradual. In accord with the predictions of polyelectrolyte theory we find lp∝1/κ2 where κ is the inverse Debye-screening length.