Department of Molecular and Cell Biology, Howard Hughes Medical Institute, University of California at Berkeley, Berkeley, California 94720, USA. doudna@berkeley.edu
Evolution has resoundingly favored protein enzymes over RNA-based catalysts, yet ribozymes occupy important niches in modern cell biology that include the starring role in catalysis of protein synthesis on the ribosome. Recent results from structural and biochemical studies show that natural ribozymes use an impressive range of catalytic mechanisms, beyond metalloenzyme chemistry and analogous to more chemically diverse protein enzymes. These findings make it increasingly possible to compare details of RNA- and protein-based catalysis.