Talk abstracts

Talk on Saturday 11:40-12:00pm submitted by Charles Hoogstraten

Mechanism of the hairpin ribozyme: Thermodynamics and kinetics of intermolecular domain docking

Charles G. Hoogstraten (Biochemistry & Molecular Biology, Michigan State University), Minako Sumita (Biochemistry & Molecular Biology, Michigan State University), Kristine R. Julien (Biochemistry & Molecular Biology, Michigan State University)

Abstract:
We have developed an intermolecular system for domain docking in the hairpin ribozyme as a simple model for the formation of tertiary structure in RNA. Our ultimate goal is to map out the free energy surface for the conformational changes involved in tertiary structure formation using comparisons of the conformational dynamics in free and bound states of the individual loops. Toward this end, we report progress in the biophysical characterization of this interaction including isothermal titration calorimetry analysis of docking thermodynamics, an exploration of the role(s) of monovalent and multivalent cations in docking, and a preliminary analysis of docking kinetics using surface plasmon resonance. In many respects, our data are in gratifying agreement with earlier biochemical results on this system (Hampel, Walter, and Burke, Biochemistry 37, 14672-14682, 1998). The current results lay a strong biophysical foundation for future NMR studies of the docking transition.

Keywords: hairpin ribozyme, RNA tertiary structure, thermodynamics