The mechanism of prumycin action.

Examination of the effects of prumycin on sensitlve Botrytis cinerea and Sarcina lutea showed that inhibition of protein synthesis in both organisms and reduction in ribonucleic acid synthesis in Botrytis cinerea are among the mechanisms of action. The inhibition of RNA biosynthesis in Botrytis cinerea is probably a secondary effect resulting from the termination of protein synthesis rather than a direct inhibition. In acell-free protein-synthesizing system obtained from crushed Botrytis cinerea cells, incorporation ofL-phenylalanine-hC into polyphenylalanine(with polyuridylic acid as synthetic messenger)was inhibited by prumycin. Ribosome binding studies indicated that prumycin did not effect its inhibition at the ribosomal stage of protein synthesis.