Escherichia coli allows efficient modular incorporation of newly isolated quinomycin biosynthetic enzyme into echinomycin biosynthetic pathway for rational design and synthesis of potent antibiotic unnatural natural product.

ABSTRACT: Natural products display impressive activities against a wide range of targets, including viruses, microbes, and tumors. However, their clinical use is hampered frequently by their scarcity and undesirable toxicity. Not only can engineering Escherichia coli for plasmid-based pharmacophore biosynthesis offer alternative means of simple and easily scalable production of valuable yet hard-to-obtain compounds, but also carries a potential for providing a straightforward and efficient means of preparing natural product analogs. The quinomycin family of nonribosomal peptides, including echinomycin, triostin A, and SW-163s, are important secondary metabolites imparting antibiotic antitumor activity via DNA bisintercalation. Previously we have shown the production of echinomycin and triostin A in E. coli using our convenient and modular plasmid system to introduce these heterologous biosynthetic pathways into E. coli. However, we have yet to develop a novel biosynthetic pathway capable of producing bioactive unnatural natural products in E. coli. Here we report an identification of a new gene cluster responsible for the biosynthesis of SW-163s that involves previously unknown biosynthesis of (+)-(1S, 2S)-norcoronamic acid and generation of aliphatic side chains of various sizes via iterative methylation of an unactivated carbon center. Substituting an echinomycin biosynthetic gene with a gene from the newly identified SW-163 biosynthetic gene cluster, we were able to rationally re-engineer the plasmid-based echinomycin biosynthetic pathway for the production of a novel bioactive compound in E. coli.

SUBMITTER: Watanabe K 

PROVIDER: S-EPMC2757413 | biostudies-literature | 2009 Jul

REPOSITORIES: biostudies-literature