Degradation of 23S rRNA in Azithromycin-Treated Ribonuclease Mutants of <em>Escherichia coli</em>.

<p>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 <em>Escherichia coli</em> 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 <em>Escherichia coli</em> 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 <em>Escherichia coli</em>.</p>

Name thesis:degree_name

MS (Master of Science)

Level thesis:degree_level

Thesis - unrestricted

Discipline thesis:degree_discipline

Biomedical Sciences

Year dc:date.issued

2004

Author dc:creator

• Silvers, Jessica A.

• ribosome
• rRNA
• azithromycin
• 50S
• 23S
• ribonucleases
• Medical Sciences
• Medicine and Health Sciences

Statement dc:rights

• Copyright by the authors.

Repository record dc:identifier

https://dc.etsu.edu/etd/957

OAI identifier oai:identifier

oai:dc.etsu.edu:etd-2114