Role of valine and isoleucine as regulators of actinomycin peptide formation by Streptomyces chrysomallus.

Katz, Edward (Rutgers, The State University, New Brunswick, N. J.), Clarence R. Waldron, and Mary Lou Meloni. Role of valine and isoleucine as regulators of actinomycin peptide formation by Streptomyces chrysomallus. J. Bacteriol. 82:600-608. 1961-d-Valine is an effective inhibitor of actinomycin synthesis by Streptomyces chrysomallus; l-valine stimulates actinomycin production and reverses the inhibition due to the d-enantiomorph. The incorporation of l-valine into the medium results, particularly, in a marked increase in actinomycin IV formation. In studies with various isoleucine isomers it was shown that l-isoleucine enhances actinomycin VII production; the principal effect of d-alloisoleucine and, especially, d-isoleucine, is to bring about synthesis of two new actinomycins which contain N-methylisoleucine. Both l- and d-threonine were observed to have an effect similar to that obtained with l-isoleucine. An interpretation of these findings has been discussed.