BIOLOGY 1A03 Lecture Notes - Lecture 8: Chloramphenicol, Gentamicin, Enzyme

• School: McMaster University
• Department: Biology
• Course: BIOLOGY 1A03
• Professor: Kim Dej

Document Summary

The bacterial ribosome is the target of over 50% of widely used antibiotics. Antibiotics could stop every step in translation process. Major functional sites and target sites for antibiotics: trna binding sites: a, p and e, mrna path. Interfering with the delivery of trnas to the a-site. Prevent transfer of trna from a to p site- no elongation: misreading. Oxazolidinones (linezolid) block the association of the large subunit (called 50s) Sit in ptc (a ribosomal rna-lined domain) blocking the peptidyl transferase reaction. Nascent peptides leave the ribosome via the exit tunnel. Interferes with amino acyl translocation (transfer of trna at the a site to the p site) Modification of prokaryotic ribosomal target: ribosomal mutation (random) that confers a selective advantage, ribosomal rna (rrna) mutation, mutation that alters ribosomal protein targets. Or: chemical modification of ribosomal target, modification of rrna, no longer bound by antibiotic. Enzyme coded by a gene introduced into the bacterial cell.