Probing DNA and RNA single molecules with a double optical tweezer.
A double-tweezer setup is used to induce mechanical stress in systems of molecular biology. A double strand of DNA is first stretched and the data is compared to precedent experiments to check the experimental setup. Then a short foldable fragment of RNA is probed; the typical unfolding/refolding hysteresis behaviour of this kind of construction is shown and followed by a study of its elasticity and a comparison to a worm-like chain model. Eventually, we describe the unfolding of a larger RNA structure, which unfolds by multiple steps. We show that this unfolding is not reversible and that it presents numerous unfolding pathways.
Laboratoire de Nanobiophysique, UMR CNRS 7083, ESPCI, 10 rue Vauquelin, 75231, Paris Cedex 05, France.
P
P
Mangeol
D
D
Côte
T
T
Bizebard
O
O
Legrand
U
U
Bockelmann
D004247:DNA / Q000737:chemistry* / Q000648:ultrastructure; D004926:Escherichia coli / Q000235:genetics; D018625:Microscopy, Atomic Force / Q000295:instrumentation / Q000379:methods; D008958:Models, Molecular; D008961:Models, Structural; D009691:Nucleic Acid Denaturation; D012313:RNA / Q000737:chemistry* / Q000648:ultrastructure; D012329:RNA, Bacterial / Q000737:chemistry; D012335:RNA, Ribosomal / Q000737:chemistry
D012329:RNA, Bacterial; D012335:RNA, Ribosomal; D012313:RNA; D004247:DNA