title: Reversible unfolding of single RNA molecules by mechanical force.
abstract: Here we use mechanical force to induce the unfolding and refolding of single RNA molecules: a simple RNA hairpin, a molecule containing a three-helix junction, and the P5abc domain of the Tetrahymena thermophila ribozyme. All three molecules (P5abc only in the absence of Mg2+) can be mechanically unfolded at equilibrium, and when kept at constant force within a critical force range, are bi-stable and hop between folded and unfolded states. We determine the force-dependent equilibrium constants for folding/unfolding these single RNA molecules and the positions of their transition states along the reaction coordinate.
authors.affiliation: Department of Chemistry, Howard Hughes Medical Institute, University of California, Berkeley, CA 94720, USA. jliphard@alice.berkeley.gov
authors.forename: J
authors.initials: J
authors.lastname: Liphardt
authors.forename: B
authors.initials: B
authors.lastname: Onoa
authors.forename: S B
authors.initials: SB
authors.lastname: Smith
authors.forename: I
authors.initials: I
authors.lastname: Tinoco
authors.forename: C
authors.initials: C
authors.lastname: Bustamante
mesh_terms: D000818:Animals; D001483:Base Sequence; D004492:Edetic Acid; D007700:Kinetics; D008274:Magnesium; D008863:Microspheres; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D011137:Polystyrenes; D012313:RNA / Q000737:chemistry*; D020871:RNA Stability; D016337:RNA, Catalytic / Q000737:chemistry*; D013314:Stress, Mechanical; D016808:Tetrahymena thermophila; D013816:Thermodynamics
chemical_list: D011137:Polystyrenes; D016337:RNA, Catalytic; D012313:RNA; D004492:Edetic Acid; D008274:Magnesium