The functions of RNA include coding (for protein,RNA,and DNA),gene regulation,catalysis,and immunomodulation.The overall goal of Gang CHEN research group is to better understand the structures and the physical-chemical properties of RNAs and RNA-ligand complexes to provide deeper insight into and to facilitate precise control of the diverse biological functions involving RNA.We have used analytical optical tweezers force spectroscopy and bulk fluorescence assays to elucidate how non-nearest-neighbor sequences and ligand binding affect RNA structure and dynamics.Our single-moleculenanomanipulation studies show that deletion of a single hydrogen bond allosterically affects RNA stabiIity and dynamics.Our ensemble fluorescence studies reveal that protein binding and tertiary interactions modulate RNA dynamics in a distance and structure dependent manner.