Role of tension and twist in single-molecule DNA condensation.
Using magnetic tweezers, we study in real time the condensation of single DNA molecules under tension. We find that DNA condensation occurs via discrete nucleated events. By measuring the influence of an imposed twist, we show that condensation is initiated by the formation of a plectonemic supercoil. This demonstrates a strong interplay between the condensation transition and externally imposed mechanical constraints.
Besteman
K
K
Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628CJ Delft, The Netherlands.
Hage
S
S
Dekker
N H
NH
Lemay
S G
SG
D055592:Biophysical Phenomena; D001703:Biophysics; D004247:DNA / Q000737:chemistry* / Q000648:ultrastructure*; D008280:Magnetics; D018625:Microscopy, Atomic Force; D009690:Nucleic Acid Conformation; D013816:Thermodynamics
D004247:DNA