RNA HOLDS KEY TO PROTEIN SYNTHESIS

Abstract

The best evidence yet that, before there were proteins, there was once a world in which RNA both provided genetic information and catalyzed chemical reactions comes from a trio of papers in the current issue of Science. In a tour de force of X-ray crystallography, chemists at Yale University have located most of the atoms in the gigantic apparatus that cells use to link amino acids together into proteins. The heart of the apparatus where peptide bonds form, they find, is composed entirely of RNA The Yale chemists have resolved the structure of the large subunit of the ribosome [Science, 289, 905, 920, and 947 (2000)]. Ribosomes in cells from all classes of organisms have so many common features that biologists believe the structure itself has been preserved essentially unchanged since the very earliest days of life's history. The Yale structure answers the chicken and egg problem of protein synthesis, says Thomas A. Steitz, who, ...