Unraveling the structural complexity in a single-stranded RNA tail: implications for efficient ligand binding in the prequeuosine riboswitch.

Published

Journal Article

Single-stranded RNAs (ssRNAs) are ubiquitous RNA elements that serve diverse functional roles. Much of our understanding of ssRNA conformational behavior is limited to structures in which ssRNA directly engages in tertiary interactions or is recognized by proteins. Little is known about the structural and dynamic behavior of free ssRNAs at atomic resolution. Here, we report the collaborative application of nuclear magnetic resonance (NMR) and replica exchange molecular dynamics (REMD) simulations to characterize the 12 nt ssRNA tail derived from the prequeuosine riboswitch. NMR carbon spin relaxation data and residual dipolar coupling measurements reveal a flexible yet stacked core adopting an A-form-like conformation, with the level of order decreasing toward the terminal ends. An A-to-C mutation within the polyadenine tract alters the observed dynamics consistent with the introduction of a dynamic kink. Pre-ordering of the tail may increase the efficacy of ligand binding above that achieved by a random-coil ssRNA. The REMD simulations recapitulate important trends in the NMR data, but suggest more internal motions than inferred from the NMR analysis. Our study unmasks a previously unappreciated level of complexity in ssRNA, which we believe will also serve as an excellent model system for testing and developing computational force fields.

Full Text

Duke Authors

Cited Authors

  • Eichhorn, CD; Feng, J; Suddala, KC; Walter, NG; Brooks, CL; Al-Hashimi, HM

Published Date

  • February 2012

Published In

Volume / Issue

  • 40 / 3

Start / End Page

  • 1345 - 1355

PubMed ID

  • 22009676

Pubmed Central ID

  • 22009676

Electronic International Standard Serial Number (EISSN)

  • 1362-4962

Digital Object Identifier (DOI)

  • 10.1093/nar/gkr833

Language

  • eng

Conference Location

  • England