Letters pubs.acs.org/acschemicalbiology
High-Titer Heterologous Production in E. coli of Lyngbyatoxin, a Protein Kinase C Activator from an Uncultured Marine Cyanobacterium Sarah E. Ongley,† Xiaoying Bian,‡ Youming Zhang,§ Rocky Chau,† William H. Gerwick,∥ Rolf Müller,*,‡ and Brett A. Neilan*,† †
School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney 2052, Australia Department of Microbial Natural Products, Helmholtz Institute for Pharmaceutical Research Saarland, Helmholtz Centre for Infection Research and Department of Pharmaceutical Biotechnology, Saarland University, Saarbrücken 66041, Germany § Shandong University-Helmholtz Joint Institute of Biotechnology, State Key Laboratory of Microbial Technology, Shandong University, Shanda Nanlu 27, 250100 Jinan, P. R. China ∥ Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, and Skaggs School of Pharmacy and Pharmaceutical Science, University of California-San Diego, La Jolla, California 92093, United States ‡
S Supporting Information *
ABSTRACT: Many chemically complex cyanobacterial polyketides and nonribosomal peptides are of great pharmaceutical interest, but the levels required for exploitation are difficult to achieve from native sources. Here we develop a framework for the expression of these multifunctional cyanobacterial assembly lines in Escherichia coli using the lyngbyatoxin biosynthetic pathway, derived from a marine microbial assemblage dominated by the cyanobacterium Moorea producens. Heterologous expression of this pathway afforded high titers of both lyngbyatoxin A (25.6 mg L−1) and its precursor indolactam-V (150 mg L−1). Production, isolation, and identification of all expected chemical intermediates of lyngbyatoxin biosynthesis in E. coli also confirmed the previously proposed biosynthetic route, setting a solid chemical foundation for future pathway engineering. The successful production of the nonribosomal peptide lyngbyatoxin A in E. coli also opens the possibility for future heterologous expression, characterization, and exploitation of other cyanobacterial natural product pathways.
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cyanobacteria, typically featuring extensive post-translational modifications, have previously been expressed in Escherichia coli.15−18 Furthermore, the expression of small stand-alone tailoring enzymes from cyanobacterial nonribosomal peptide synthetase (NRPS) and polyketide synthase (PKS) pathways has also been achieved allowing characterization of their biochemistry in vitro.19−22 However, the heterologous expression of a complete cyanobacterial PKS or NRPS biosynthetic pathway to yield the final biosynthetic product has proven very difficult to attain. The hybrid PKS/NRPS barbamide derivative, 4-O-demethylbarbamide, is to our knowledge the only successful heterologous production of a cyanobacterial compound of this type,23 although yield in a Streptomyces host was very low (
