Ligation of RNA Molecules by the Hairpin Ribozyme
Ribozymes are capable of catalyzing a variety of RNA cleavage, ligation, and splicing reactions. Of these three reaction types, ligation is the least-studied, primarily because of practical difficulties in achieving reasonable reaction efficiencies. Ribozyme-catalyzed ligation reactions are of interest for several reasons. First, ligation is the critical step in a powerful in vitro selection scheme that has been developed in our laboratory (1 –3 ). Second, understanding the chemistry, thermodynamics, and kinetics of the ligation reaction is important for understanding the reaction in vitro and in the native biological environment of the ribozyme. Third, learning to exploit the ligation reaction will enhance our ability to manipulate RNA molecules in vitro, and may directly contribute to our efforts to develop a technology of engineered ribozymes for targeted RNA cleavage and recombination in vivo.