title: Single-Molecule Approaches for the Characterization of Riboswitch Folding Mechanisms.
abstract: Riboswitches are highly structured RNA molecules that control genetic expression by altering their structure as a function of metabolite binding. Accumulating evidence suggests that riboswitch structures are highly dynamic and perform conformational exchange between structural states that are important for the outcome of genetic regulation. To understand how ligand binding influences the folding of riboswitches, it is important to monitor in real time the riboswitch folding pathway as a function of experimental conditions. Single-molecule FRET (sm-FRET) is unique among biophysical techniques to study riboswitch conformational changes as it allows to both monitor steady-state populations of riboswitch conformers and associated interconversion dynamics. Since FRET fluorophores can be attached to virtually any nucleotide position, FRET assays can be adapted to monitor specific conformational changes, thus enabling to deduce complex riboswitch folding pathways. Herein, we show how to employ sm-FRET to study the folding pathway of the S-adenosylmethionine (SAM) and how this can be used to understand very specific conformational changes that are at the heart of riboswitch regulation mechanism.
authors.affiliation: Département de Biologie, Faculté des Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada, J1K 2R1.
authors.forename: Julien
authors.initials: J
authors.lastname: Boudreault
authors.affiliation: School of Physics and Astronomy, University of St. Andrews, St. Andrews, UK.
authors.forename: D Cibran
authors.initials: DC
authors.lastname: Perez-Gonzalez
authors.affiliation: School of Physics and Astronomy, University of St. Andrews, St. Andrews, UK.
authors.forename: J Carlos
authors.initials: JC
authors.lastname: Penedo
authors.affiliation: Département de Biologie, Faculté des Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada, J1K 2R1. Daniel.Lafontaine@USherbrooke.ca.
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Lafontaine
mesh_terms: D031541:Fluorescence Resonance Energy Transfer / Q000379:methods; D005786:Gene Expression Regulation; D006801:Humans; D008024:Ligands; D036103:Nanotechnology; D009690:Nucleic Acid Conformation; D059370:RNA Folding / Q000235:genetics*; D058928:Riboswitch / Q000235:genetics*; D012436:S-Adenosylmethionine / Q000737:chemistry
chemical_list: D008024:Ligands; D058928:Riboswitch; D012436:S-Adenosylmethionine
keywords: Metabolite-sensing; RNA folding; Riboswitch; S-adenosylmethionine; Single-molecule FRET