Lysine Biosynthesis in Streptomyces lipmanii : Implications in Antibiotic Biosynthesis

Streptomyces lipmanii produces two beta-lactam antibiotics, penicillin N and 7-(5-amino-5-carboxyvaleramido)-7-methoxycephalosporanic acid. Both antibiotics contain alpha-aminoadipic acid side chains. In similar antibiotics produced by certain fungi, the alpha-aminoadipoyl moiety is derived from an intermediate in lysine biosynthesis. Our findings indicate, however, that in S. lipmanii, lysine is synthesized via alpha, epsilon-diaminopimelic acid-an entirely different biosynthetic route. This finding suggests not only a unique mechanism for the derivation of alpha-aminoadipate, but also that the system may be particularly amenable to genetic manipulation.