Activation of a Cryptic Gene Cluster in Lysobacter enzymogenes Reveals a Module/Domain Portable Mechanism of Nonribosomal Peptide Synthetases in the Biosynthesis of Pyrrolopyrazines.

Lysobacter are considered "peptide specialists". However, many of the nonribosomal peptide synthetase genes are silent. Three new compounds were identified from L. enzymogenes upon activating the six-module-containing led cluster by the strong promoter PHSAF. Although ledD was the first gene under PHSAF control, the second gene ledE was expressed the highest. Targeted gene inactivation showed that the two-module LedE and the one-module LedF were selectively used in pyrrolopyrazine biosynthesis, revealing a module/domain portable mechanism.