Serra, Martin The ultimate goal of this research project is to characterize the molecular interactions responsible for the structural stability of RNA. The fundamental role played by divalent metal ions (Mg +2 ) in nucleic acid biochemistry highlights the need to understand better the dependence of divalent metal ions on RNA structural stability. The specific aim of this project is to investigate metal ion binding (specifically Mg +2 ) to small and structurally well-defined RNA oligomers. The interaction of metal ions with common RNA secondary structural motifs (i.e. duplex, hairpin, terminal mismatch, bulge and internal loop) will be investigated. This study is designed to determine the physiochemical parameters underlying binding of metal ion to these RNA structural motifs under physiological conditions. These studies will combine both thermal stability and binding studies to achieve a better understanding of the nature of RNA-metal interactions.