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.
","abstract_html":"<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>","abstract_has_math":false,"creators":["Silvers, Jessica A."],"institution":null,"degree_name":"MS (Master of Science)","degree_level":"Thesis - unrestricted","degree_discipline":"Biomedical Sciences","degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2004,"date_issued":"2004-12-18T08:00:00Z","date_published":"2004-12-18T08:00:00Z","updated_at":"2026-07-24T02:19:35Z","subjects":["ribosome","rRNA","azithromycin","50S","23S","ribonucleases","Medical Sciences","Medicine and Health Sciences"],"languages":[],"rights":["Copyright by the authors."],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://dc.etsu.edu/etd/957","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Silvers, Jessica A."]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.issued","label":"Date","values":["2004-12-18T08:00:00Z"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Biomedical Sciences"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis - unrestricted"]},{"key":"thesis:degree_name","label":"Degree Name","values":["MS (Master of Science)"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["ribosome","rRNA","azithromycin","50S","23S","ribonucleases","Medical Sciences","Medicine and Health Sciences"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["Copyright by the authors."]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://dc.etsu.edu/context/etd/article/2114/viewcontent/SilversJ112204f.pdf","https://dc.etsu.edu/etd/957"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["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.
"]},{"key":"dc:title","label":"Title","values":["Degradation of 23S rRNA in Azithromycin-Treated Ribonuclease Mutants of Escherichia coli."]}]}],"canonical_facts":{"dc:creator":["Silvers, Jessica A."],"dc:date.issued":["2004-12-18T08:00:00Z"],"dc:description.abstract":["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.
"],"dc:identifier":["https://dc.etsu.edu/context/etd/article/2114/viewcontent/SilversJ112204f.pdf","https://dc.etsu.edu/etd/957"],"dc:rights":["Copyright by the authors."],"dc:subject":["ribosome","rRNA","azithromycin","50S","23S","ribonucleases","Medical Sciences","Medicine and Health Sciences"],"dc:title":["Degradation of 23S rRNA in Azithromycin-Treated Ribonuclease Mutants of Escherichia coli."],"thesis:degree_discipline":["Biomedical Sciences"],"thesis:degree_level":["Thesis - unrestricted"],"thesis:degree_name":["MS (Master of Science)"]},"updated_at":"2026-07-24T02:19:35Z"}