Title | Probing mechanism and transition state of RNA refolding |
Publication Type | Journal Article |
Year of Publication | 2010 |
Authors | Fürtig B, Wenter P, Pitsch S, Schwalbe H |
Journal | ACS Chem. Biol. |
Volume | 5 |
Issue | 8 |
Pagination | 753-765 |
Accession Number | 189 |
Abstract | Kinetics and the atomic detail of RNA refolding are only poorly understood. It has been proposed that conformations with transient base pairing interaction are populated during RNA refolding but a detailed description of those states is lacking. By NMR and CD spectroscopy, we examined the refolding of a bistable RNA and the influence of urea, Mg2+ and spermidine on its refolding kinetics. The bistable RNA serves as a model system and exhibits two almost equally stable groundstate conformations. We designed a photolabile caged RNA to selectively stabilize one of the two groundstate conformations and trigger RNA refolding by in-situ light irradiation in the NMR spectrometer. We can show that the refolding kinetics of the bistable RNA is modulated by urea, Mg2+ and spermidine by different mechanisms. From a statistical analysis based on elementary rate constants, we deduce the required number of base pairs that need to be destabilized during the refolding transition and propose a model for the transition state of the folding reaction. |
URL | http://pubs.acs.org/doi/abs/10.1021/cb100025a |
DOI | 10.1021/cb100025a |