Our understanding of the mechanisms regulating gene expression, which determine the patterns of growth and development in all living organisms, ultimately involves the elucidation of the detailed and dy namic interactions of proteins with nucleic acids -both DNA and RNA. Until recently the commonly presented view of the DNA double helix as visualized on the covers of many textbooks and journals - was as a monotonous static straight rod incapable in its own right of directing the processes necessary for the conservation and selective reading of genetic information. This view, although perhaps...