Direct capture and heterologous expression of Salinispora natural product genes for the biosynthesis of enterocin

Abstract

Heterologous expression of secondary metabolic pathways is a promising approach for the discovery and characterization of bioactive natural products. Herein we report the first heterologous expression of a natural product from the model marine actinomycete genus Salinispora. Using the recently developed method of yeast-mediated transformation-associated recombination for natural product gene clusters, we captured a type II polyketide synthase pathway from Salinispora pacifica with high homology to the enterocin pathway from Streptomyces maritimus and successfully produced enterocin in two different Streptomyces host strains. This result paves the way for the systematic interrogation of Salinispora's promising secondary metabolome.

Figure 1

Comparison of the enterocin (enc) gene clusters of Streptomyces maritimus and Salinispora pacifica CNT-150. Numbered genes in S. pacifica are further described in Table 1.

Figure 2

Heterologous expression of enterocin. (A) HPLC chromatograms of extracts of the heterologous host Streptomyces coelicolor M1146 with and without the expression plasmid pBB01 as well as the natural producer strains Streptomyces maritimus and Salinispora pacifica CNT-150. Detection at 254 nm. (B) Structure of enterocin.