文摘
Leinamycin (LNM, 1) biosynthesis is proposed to involve 尾-alkylation of the polyketide intermediate, catalyzed by LnmKLM. Inactivation of lnmK, lnmL, or lnmM afforded mutant strains that accumulated LNM K-1 (2), K-2 (3), K-3 (4), and isomers LNM K-1鈥?(5), K-2鈥?(6), and K-3鈥?(7) whose polyketide origin was established by feeding experiments with sodium [1-13C]acetate. These findings confirm the indispensability of LnmKLM in 1 biosynthesis and suggest that 尾-alkylation proceeds on the growing polyketide intermediate while bound to the LNM polyketide synthase.