Research supoported under the previous award has discovered that the synthesis of many ribosomal proteins (r-proteins) is feedback regulated at the level of translation and that this feedback mechanism plays an important role in the the balanced synthesis of ribosomal components in growing bacteiral cells. Several r-proteins have been identified as repressors and their interaction with mRNA target sites investigated, concentrating mainly on the L11, the spc and the alpha r-protein operon systems. The new award will continue these studies with emphasis on the role of these operons in translational regulation of r-protein synthesis, and the presumed translational feedback regulation of RNA polymerase subunit synthesis by RNA polymerase. In addition, the mechanisms involved in the global regulation of total protein synthesis will be studied using genetic markers. The proposed reseach will make a significant contribution to our understanding of not only the principles of the feedback mechanisms involved in the regulation of ribosome synthesis, but also the detailed mechanism of ribosome function and its regulation in general.