MS (Master of Science)
Date of Award
Committee Chair or Co-Chairs
W. Scott Champney
Jane E. Raulston, Douglas P. Thewke, Brian P. Rowe
Azithromycin, a macrolide antibiotic, specifically binds to the 50S ribosomal subunit of bacterial ribosomes and inhibits translation. Azithromycin also prevents 50S ribosomal subunit assembly by binding to a 50S ribosomal subunit precursor particle. When exposed to azithromycin, several ribonucleases in wild-type Escherichia coli cells degrade antibiotic-bound 50S precursor particles. Presumably, cells expressing one or more mutated ribonucleases will degrade the antibiotic-bound precursor less efficiently, resulting in increased sensitivity to the antibiotic. To test this, eight ribonucleaseûdeficient strains of Escherichia coli were grown in the presence or absence of azithromycin. Cell viability, growth rates, and protein synthesis rates were measured. Degradation of 23S rRNA was examined by hybridization with a 23S specific probe. Ribonuclease II and polynucleotide phosphorylase mutants demonstrated hypersensitivity to the antibiotic and showed a greater extent of 23S rRNA accumulation, suggesting that these two ribonucleases are important for 23S rRNA turnover in azithromycin-treated Escherichia coli.
Thesis - unrestricted
Silvers, Jessica A., "Degradation of 23S rRNA in Azithromycin-Treated Ribonuclease Mutants of Escherichia coli." (2004). Electronic Theses and Dissertations. Paper 957. https://dc.etsu.edu/etd/957
Copyright by the authors.