Ribozymes.

RNA enzymes or ribozymes are receiving considerable attention for their potential use as highly specific inhibitors of gene expression. From the basic science perspective, the mechanisms by which ribozymes catalyze site-specific cleavage (and in some cases ligation) reactions provide exciting and active areas of scientific investigation. The most recent developments in our understanding of the molecular mechanisms of catalysis, as well as in vivo applications of ribozymes, are highlighted.