Mechanical unfolding of human telomere G-quadruplex DNA probed by integrated fluorescence and magnetic tweezers spectroscopy.

ABSTRACT: Single-molecule techniques facilitate analysis of mechanical transitions within nucleic acids and proteins. Here, we describe an integrated fluorescence and magnetic tweezers instrument that permits detection of nanometer-scale DNA structural rearrangements together with the application of a wide range of stretching forces to individual DNA molecules. We have analyzed the force-dependent equilibrium and rate constants for telomere DNA G-quadruplex (GQ) folding and unfolding, and have determined the location of the transition state barrier along the well-defined DNA-stretching reaction coordinate. Our results reveal the mechanical unfolding pathway of the telomere DNA GQ is characterized by a short distance (<1 nm) to the transition state for the unfolding reaction. This mechanical unfoldin

SUBMITTER: Long X 

PROVIDER: S-EPMC3575832 | biostudies-literature | 2013 Feb

REPOSITORIES: biostudies-literature