New Technique Reveals Subtle Force-induced Changes in Biomolecule's Conformation

A DNA four-way junction (cylinders) labeled with dyes (red and green dots) are controlled by applying force via a bead trapped in a laser beam through the linker. The DNA structure interconverts between two conformations which can be detected via fluorescence resonance energy transfer (FRET) between the two dyes. How the applied force influences the interconversion frequencies can be determined by this hybrid technique combining optical trap and single molecule FRET. Credit: Taekjip Ha, University of Illinois, Urbana-Champaign