GENETIC PROBES OF RIBOSOMAL-RNA FUNCTION

We have used a genetic approach to uncover the functional roles of rRN A in protein synthesis. Mutations were constructed in a cloned rrn ope ron by site-directed mutagenesis or isolated by genetic selections fol lowing random mutagenesis. We have identified mutations that affect ea ch step in the process of translation. The data are consistent with th e results of biochemical and phylogenetic analyses but, in addition, h ave provided novel information on regions of rRNA not previously inves tigated.