In recent years, unprecedented advances in many aspects of the molecular biology of nucleic acids have been witnessed. The area of RNA chemistry has undergone a kind of explosion, with a huge interest in RNA-mediated catalysis. At the same time, our structural understanding of DNA-protein interactions has increased enormously, and the related area of RNA-protein interactions is beginning to gather pace. This softcover edition from the successful series Nucleic Acids and Molecular Biology is devoted to the structure and mechanism of ribozymes, and their potential exploitation. The subject has both important evolutionary implications and potential practical application in the development of therapeutic agents for diseases such as AIDS.