Structure elucidation and biosynthesis of lysine-rich cyclic peptides in Xenorhabdus nematophila

Thirteen novel PAX (peptide-antimicrobial-Xenorhabdus) peptides were identified in Xenorhabdus nematophilaHGB081. Their structures including the absolute configuration were elucidated using a combination of labeling experiments, detailed MS/MS experiments, the advanced Marfey's method, and a detailed analysis of the biosynthesis gene cluster, which was identified as well.