The Catalytic Potential of RNA

In 1982, T. Cech and coworkers showed that an ribonucleic acid (RNA) molecule from a ciliated protozoan could act like a protein and catalyze the biochemical reactions necessary for its own maturation. The discovery of catalytic RNA molecules has led to a re-examination of biological catalysis and of the role of RNA in cellular metabolism. The accurate excision of the intron and the concomitant ligation of the exons is accomplished by a single catalytic activity that resides within the intron. The RNA molecule must fold into an appropriate three-dimensional structure in order to express its catalytic activity. Analysis of catalytic RNAs from many organisms has led to the recognition of four major categories of ribozymes. The activity of catalytic RNA molecules is not restricted to self-splicing. If RNA catalysis is a special property that requires a long period of evolutionary development, then existing ribozymes are likely to provide the best starting point for exploring the catalytic potential of RNA.