Which antibiotic inhibits RNA polymerase in bacteria, thereby blocking transcription?

Study for the Cengage Microbiology Test with helpful multiple choice questions and detailed explanations. Ace your exam with confidence!

Multiple Choice

Which antibiotic inhibits RNA polymerase in bacteria, thereby blocking transcription?

Blocking transcription in bacteria is achieved by targeting the enzyme that copies their DNA into RNA. Rifampin binds specifically to the bacterial RNA polymerase and prevents the initiation of RNA synthesis, so transcription cannot proceed. This selective action stems from rifampin’s affinity for the bacterial enzyme, leaving human RNA polymerases largely unaffected. In contrast, penicillin disrupts cell wall synthesis, tetracycline interferes with protein synthesis at the 30S ribosomal subunit, and vancomycin also targets the cell wall. Resistance to rifampin can develop through mutations in the bacterial RNA polymerase gene (rpoB), underscoring the importance of using it appropriately in combination therapies.

Blocking transcription in bacteria is achieved by targeting the enzyme that copies their DNA into RNA. Rifampin binds specifically to the bacterial RNA polymerase and prevents the initiation of RNA synthesis, so transcription cannot proceed. This selective action stems from rifampin’s affinity for the bacterial enzyme, leaving human RNA polymerases largely unaffected. In contrast, penicillin disrupts cell wall synthesis, tetracycline interferes with protein synthesis at the 30S ribosomal subunit, and vancomycin also targets the cell wall. Resistance to rifampin can develop through mutations in the bacterial RNA polymerase gene (rpoB), underscoring the importance of using it appropriately in combination therapies.

More practice questions