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

Abstract

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.

Natural products from thioester reductase containing biosynthetic pathways

“…Le-pyrrolopyrazines A and C are cyclized dipeptides reported by Li and coworkers in 2017. 133 The study was also the first report of a third analog, Le-pyrrolopyrazine B, as a NP. 134 The structures of Le-pyrrolopyrazines A, B, and C are differentiated based on whether valine, leucine, or isoleucine, respectively, are incorporated with a conserved proline during biosynthesis (Fig.…”

Nature's Combinatorial Biosynthesis Produces Vatiamides A–F

“…Examples of stuttering, [25] halting, [26] out-of-order module processing, [27] skipping, [28][29][30][31][32] bidirectionality, [33] and combinations thereof [26] have been reported in various NP biosynthetic pathways.W er eport here the first characterized example to date of anative reversal of selectivity in aPKS/NRPS context. Thepromiscuity enabled by identical dds adds anew element to the combinatorial possibilities of both heterologous and native pathways.One may speculate that the origin in ASI is synergistic defensive toxicity imparted by the combination of more than one of the three head groups,o rs eparate environmental targets for each.…”

Integrating genomics and metabolomics for scalable non-ribosomal peptide discovery

“…While in many NRPSs each A-domain incorporates exactly one designated amino acid and the sequence of amino acids in NRP matches the order of the A-domains in the BGC 13,31,32 (see Supplementary Fig. 1a), there are many NRP families that violate this pattern 7,11,[32][33][34][35][36][37][38][39] . Since an NRPS system may have multiple assembly lines 40 , one needs to consider different combinations of NRPS units encoded by each open reading frames (ORFs) for finding the core NRPs 27,40 .…”

“…For example, during biosynthesis of rhabdopeptides 34,38 and lugdunins 7 , a single ORF encodes for one Val-specific NRPS module that loads multiple Val in the final NRPs. Moreover, in some NRPS assembly lines, the A-domains in some ORFs do not contribute to the core NRP 32,37,41 (see Supplementary Fig. 1c).…”