title: Inhibition by thiopeptin of bacterial protein synthesis.
abstract: Thiopeptin, a sulfur-containing antibiotic, was found to inhibit protein synthesis in a bacterial ribosomal system. The pretreatment of ribosomal subunits with the antibiotic revealed that thiopeptin may act on the 50 S ribosomal subunit. The elongation of peptide chain on the ribosome is more profoundly blocked by the antibiotic than the initiation of protein synthesis. It was demonstrated that thiopeptin inhibits elongation factor (EF)-Tu-dependent GTP hydrolysis and binding of aminoacyl-tRNA to the ribosome. The peptidyl transferase-catalyzed puromycin reaction is not significantly affected by the antibiotic. Thiopeptin inhibits EF-G-associated GTPase reaction, and translocation of peptidyl-tRNA and mRNA from the acceptor site to the donor site. Protein synthesis in ribosomal systems, obtained from rat liver and rabbit reticulocytes are insensitive to the antibiotic.
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D023181:Antimicrobial Cationic Peptides; D001426:Bacterial Proteins / Q000096:biosynthesis*; D002474:Cell-Free System; D004926:Escherichia coli / Q000378:metabolism*; D020963:GTP Phosphohydrolase-Linked Elongation Factors / Q000378:metabolism; D010441:Peptide Chain Elongation, Translational / Q000187:drug effects; D010442:Peptide Chain Initiation, Translational / Q000187:drug effects; D010445:Peptide Elongation Factors; D010455:Peptides / Q000494:pharmacology; D010458:Peptidyl Transferases / Q000378:metabolism; D012270:Ribosomes / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides; D001426:Bacterial Proteins; D010445:Peptide Elongation Factors; D010455:Peptides; C022076:thiopeptin; D010458:Peptidyl Transferases; D020963:GTP Phosphohydrolase-Linked Elongation Factors