Identification of Holrhizins E–Q Reveals the Diversity of Nonribosomal Lipopeptides in <i>Paraburkholderia rhizoxinica</i>
Hanna Chen, Haibo Zhou, Tao Sun, Jiaying Xu, Qiang Tu, Jie Yang, Youming Zhang, Xiaoying Bian
Abstract
The products of a nonribosomal peptide synthetase gene, holA, from Paraburkholderia rhizoxinica were investigated using our recently established recombineering technique. Fifteen products, including 13 new linear lipopeptides, holrhizins E–Q (2–8, 10–15), together with the two known holrhizins A and B (1, 9), were detected in the activated mutant, and their structures were identified using HRESIMS, NMR spectroscopy, Marfey’s analysis, and feeding experiments with labeled amino acids. The lipohexapeptides 1–3 and 7–14 differ in three amino acid residues and the N-terminal fatty acid chains. The diversity of the holrhizins originates from the substrate flexibility of the A4, A5, and A6 domains as well as the starter C domain in the biosynthetic pathway.