Single-molecular Dynamics of Four-way Junctions in DNA and RNA

Professor Taekjip Ha
Department of Physics
University of Illinois
Urbana-Champaign, IL

Monday, September 16, 2002
3:00 pm
3269 Beckman Institute

Abstract

Branched helical junctions are ubiquitous in nucleic acids. In DNA, the four-way junction (Holliday junction) is an essential intermediate in homologous recombination and is ahighlydynamics structure, capable of stacking conformer transitions and branch migration. Our single molecule fluorescence studies provide a useful insights into the energy landscape of Holliday junction conformer transitions and branch migration. In Hairpin ribozyme, RNA four-way junction is an important structural element that enhances the active site formation by several orders of magnitudes. Our single molecule study suggests a plausible mechanism of how the junction achieves this remarkable feat.

Tea and coffee will be served in R3151 Beckman Institute at 2:15pm.