title: Charge screening in RNA: an integral route for dynamical enhancements.
abstract: Electrostatic interactions of RNA are at the center of determining the dynamical flexibility and structural stability. By analysing neutron scattering spectroscopy, we show that fast dynamics of hydrated tRNA on ps to ns timescales increases with stronger charge screening, while its structural stability either increases or remains largely unchanged. An unprecedented electrostatic threshold for the onset of additional flexibility is induced from the correlation between the charge-screening density of counterions and the promoted dynamical properties. The results demonstrate that the enhanced dynamical flexibility of tRNA originates from local conformational relaxation coupled with stabilized charge screening rather than governed by fluctuation of hydrated counterions. The present study casts light on the specificity of electrostatic interactions in the thermodynamic balance between the dynamical flexibility and structural stability of RNA.
authors.affiliation: Center for Self-assembly and Complexity (CSC), Institute for Basic Science (IBS), Pohang 37673, South Korea. jhroh@ibs.re.kr and Biomolecular Science, University of Science and Technology, Daejeon 34113, South Korea.
authors.forename: Joon Ho
authors.initials: JH
authors.lastname: Roh
authors.affiliation: NIST Center for Neutron Research, National Institute of Standards and Techonology, Gaithersburg, Maryland 20899, USA and Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, USA.
authors.forename: Madhu
authors.initials: M
authors.lastname: Tyagi
authors.affiliation: Center for Self-assembly and Complexity (CSC), Institute for Basic Science (IBS), Pohang 37673, South Korea. jhroh@ibs.re.kr.
authors.forename: Pulakesh
authors.initials: P
authors.lastname: Aich
authors.affiliation: Center for Self-assembly and Complexity (CSC), Institute for Basic Science (IBS), Pohang 37673, South Korea. jhroh@ibs.re.kr and Department of Chemistry, Pohang University of Science and Technology, Pohang 37673, South Korea.
authors.forename: Kimoon
authors.initials: K
authors.lastname: Kim
authors.affiliation: Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, USA.
authors.forename: R M
authors.initials: RM
authors.lastname: Briber
authors.affiliation: T. C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, Maryland 21218, USA.
authors.forename: Sarah A
authors.initials: SA
authors.lastname: Woodson
mesh_terms: D056004:Molecular Dynamics Simulation; D012343:RNA, Transfer / Q000737:chemistry*; D055672:Static Electricity
chemical_list: D012343:RNA, Transfer