Mechanical unzipping studies of RNA folding
| Quand ? |
Le 08/11/2021, de 11:00 à 12:00 |
|---|---|
| Où ? | Salle des thèses |
| Participants |
Felix Ritort |
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DNA, RNA, and proteins are polymers that fold into unique three-dimensional structures to perform their biological function. How these molecules fold is, however, not fully understood. Single-molecule force spectroscopy has revealed a valuable tool to monitor folding reactions by measuring force and molecular extension, the latter being the natural reaction coordinate in these reactions. This talk reviews recent developments to derive folding free energies in DNA and RNA hairpins using fluctuation theorems. In particular, I will present the first experimental derivation of the nearest-neighbor base-pair energies of RNA in magnesium by mechanically unzipping long RNA hairpins. The strong irreversibility of the unzipping process reveals that RNA folding is driven by the formation of small stem-loop structures that compete with the native stem, favoring the formation of alternative structures and misfolding. The diversity of structures that can form upon RNA folding correlates with its many biological functions and the complexity of RNA biophysics.