Polysome metabolism in Escherichia coli: amicetin, an antibiotic that stabilizes polysomes.

Amicetin, an aminohexosepyrimidine nucleoside antibiotic, inhibited protein synthesis in intact bacterial cells and in cell-free extracts derived from these cells. At concentrations of antibiotic which rapidly and completely inhibited protein synthesis, the polysomes in the cell were stabilized. Amicetin also inhibited the breakdown of polysomes induced by the streptogramin A antibiotics, rifampin, or puromycin, antibiotics that require peptide bond formation for expression of their action on polysomes. Thus, amicetin is another addition to the list of drugs which may be useful in studying polysome and messenger ribonucleic acid metabolism in vivo. An in vitro system is described which may be generally useful in studying polysome metabolism when antibiotic-sensitive strains are not available.