FUNCTION OF YJEE AND RIBOSOME ASSEMBLY FACTORS

Abstract

<p>Using the model organism <em>Escherichia coli</em>, we discuss herein two novel antimicrobial targets: namely, the protein YjeE and the process of ribosome assembly.</p> <p>YjeE is essential for viability and widely conserved amongst bacterial pathogens and has no human homologue. We searched for a small molecule probe of the function of YjeE to help circumvent the inadequate genetic tools that are available for studying this protein. Sensitive methods for detecting ligand binding were optimized; however, this effort yielded no inhibitors. A second approach to studying the function of YjeE was the development of a reporter using a promoter that is directly upstream of <em>yjeE </em>in <em>E. coli</em>. The activity of this promoter was tested in the presence of small molecules of known function and in diverse gene deletion backgrounds. YjeE found to be linked to the inhibition of DNA and protein translation as well as central metabolism and respiration. These interactions prompted experiments that revealed YjeE to be dispensable under anaerobic conditions.</p> <p>Many antibiotics target ribosomal protein synthesis; however, no current antibiotics target the process of ribosome biogenesis. In order to identify new biogenesis factors, the non-essential fraction of the <em>E. coli </em>genome was screened for deletions that gave rise to cold-sensitive growth. We found that genes associated with ribosome function were the most represented cold sensitive factors amongst the genes of known function. We identified and present here two new putative ribosome biogenesis factors, <em>prfC</em> and <em>ychF</em>, which had phenotypes associated with ribosome assembly defects.</p>