The mechanism of resistance to puromycin and to the puromycin-precursor O-demethyl-puromycin in Streptomyces alboniger

Ribosomes from Streptomyces alboniger are sensitive in vitro to puromycin and, to a lesser extent, to the puromycin-precursor O-demethyl-puromycin. The puromycin-inactivating enzyme (puromycin N-acetyltransferase) from S. alboniger also N-acetylates O-demethyl-puromycin. This finding indicates that in certain antibiotic-producing organisms the antibiotic-inactivating enzymes may play a role in self-defence against toxic precursor molecules.