Genome analysis of actinomycetes has revealed the presence of numerous cryptic gene clusters encoding putative natural products. These loci remain dormant until appropriate chemical or physical signals induce their expression. Here we demonstrate the use of a high-throughput genome scanning method to detect and analyze gene clusters involved in natural-product biosynthesis. This method was applied to uncover biosynthetic pathways encoding enediyne antitumor antibiotics in a variety of actinomycetes. Comparative analysis of five biosynthetic loci representative of the major structural classes of enediynes reveals the presence of a conserved cassette of five genes that includes a novel family of polyketide synthase (PKS). The enediyne PKS (PKSE) is proposed to be involved in the formation of the highly reactive chromophore ring structure (or "warhead") found in all enediynes. Genome scanning analysis indicates that the enediyne warhead cassette is widely dispersed among actinomycetes. We show that selective growth conditions can induce the expression of these loci, suggesting that the range of enediyne natural products may be much greater than previously thought. This technology can be used to increase the scope and diversity of natural-product discovery.
|Number of pages||4|
|State||Published - Feb 1 2003|
Bibliographical noteFunding Information:
Acknowledgments We thank S. Mercure, V. Dodelet, and M. Piraee for helpful discussions and J. McAlpine for critical reading of the manuscript. B.S. is a recipient of a NSF CAREER Award (MCB9733938) and a NIH Independent Scientist Award (AI51689). Enediyne studies in the Shen lab are supported in part by NIH grant CA78747. Research in the Thorson lab is supported in part by NIH grants CA84347, GM58196, and AI52218. J.S.T. is an Alfred P. Sloan Fellow.
ASJC Scopus subject areas
- Applied Microbiology and Biotechnology
- Molecular Medicine
- Biomedical Engineering