| As the factory responsible for producing proteins, ribosomes are of great importance. In bacteria, ribosomes are composed of three ribosomal RNAs (rRNA) of different sizes, and around 50 ribosomal proteins (r-protein). During ribosome biogenesis in bacteria, synthesis of rRNAs and r-proteins are both tightly regulated and coordinated to ensure robust growth. In particular, a group of cis-regulatory RNA elements located in the 5' untranslated regions or the intergenic regions in r-protein operons are responsible for the regulation of r-protein biosynthesis. Based on the fact that RNA-regulated r-protein biosynthesis is essential and universal in bacteria, such unique and varied regulatory RNAs could provide new targets for antibacterial purpose. In this thesis, we report and experimentally verify a novel r-protein L1 regulation model that contains dual L1-binding RNA motif, and for the first time, a S6:S18 dimer-binding RNA structure in the S6 operon. We also describe Escherichia coli-based and Schizosaccharomyces pombe-based reporter systems for in vivo characterization of RNA-protein interactions. So far, both in vivo systems failed to report RNA-protein interactions, and thus need further tuning. In addition, we performed phage-display to select for regulatory RNA---binding small peptides and examined their effects on bacteria viability. One selected peptide, N-TVNFKLYC, caused defective growth when overexpressed in E. coli. Yet, further studies must be conducted to verify the possibility that bacteria were killed by direct RNA-peptide interaction that disrupted the native r-protein regulation. |
