MODE OF ACTION OF BERNINAMYCIN . AN INHIBITOR OF PROTEIN BIOSYNTHESIS

Berninamycin acts as a specific inhibitor of protein synthesis in Bacillus subtilis cells. Experiments with bacterial cell-free macromolecular biosynthetic systems showed that berninamycin interferes with amino acid incorporation into peptides directed by natural messenger ribonucleic acid and synthetic polyribonucleotides. Deoxyribonucleic acid and ribonucleic acid synthesis remained unaffected in cell-free systems. Individual reaction sequences occurring during polypeptide synthesis including aminoacyl transfer ribonucleic acid formation, aggregation to the ternary aminoacyl transfer ribonucleic acid-messenger-ribosome complex, messenger attachment to ribosomes, and peptide-bond formation remained insensitive to the antibiotic. No misreading of the code was apparent in a test system sensitive to streptomycin. These data suggest that the most likely site of berninamycin interaction during polypeptide biosynthesis occurs after formation of the peptide bond and might involve interference with transfer ribonucleic acid release, movement of the nascent peptide chain on the ribosomes, or movement of the messenger. © 1969, American Chemical Society. All rights reserved.