title: Torque spectroscopy of DNA: base-pair stability, boundary effects, backbending, and breathing dynamics.
abstract: Changes in global DNA linking number can be accommodated by localized changes in helical structure. We have used single-molecule torque measurements to investigate sequence-specific strand separation and Z-DNA formation. By controlling the boundary conditions at the edges of sequences of interest, we have confirmed theoretical predictions of distinctive boundary-dependent backbending patterns in torque-twist relationships. Abrupt torque jumps are associated with the formation and collapse of DNA bubbles, permitting direct observations of DNA breathing dynamics.
authors.affiliation: Department of Bioengineering, Stanford University, Stanford, California 94305, USA.
authors.forename: Florian C
authors.initials: FC
authors.lastname: Oberstrass
authors.forename: Louis E
authors.initials: LE
authors.lastname: Fernandes
authors.forename: Paul
authors.initials: P
authors.lastname: Lebel
authors.forename: Zev
authors.initials: Z
authors.lastname: Bryant
mesh_terms: D020029:Base Pairing; D043542:DNA, Z-Form / Q000737:chemistry; D009690:Nucleic Acid Conformation; D013057:Spectrum Analysis / Q000379:methods*; D019415:Torque; D018911:Trinucleotide Repeats
chemical_list: D043542:DNA, Z-Form