S70: Discovery of novel natural products by refactoring cryptic pathways

Microorganisms are a major source of new therapeutic agents.  Sequenced genomes and metagenomes provide a tremendously rich source for discovery of novel gene clusters involved in natural product biosynthesis.  However, due to the lack of tools to efficiently identify a complete biosynthetic gene cluster, determine the role of each involved gene, and subsequently designate a function to the target gene cluster, only a tiny fraction of those putative natural product biosynthetic gene clusters have been characterized.  To overcome this limitation, my group has developed a new genomics-driven, synthetic biology enabled method to discover and produce novel natural products from sequenced genomes and metagenomes.  By taking advantage of the highly efficient yeast in vivo homologous recombination mechanism, this method synthesizes the entire expression vector containing the target gene cluster and the genetic elements needed for DNA maintenance and replication in S. cerevisiae, E. coli, and a target heterologous expression host in a single-step manner.  As proof of concept, we used the polyketide spectinabilin pathway from Streptomyces spectabilis and a cryptic pathway containing a polyketide synthase-non-ribosomal peptide synthetases from Streptomyces grieseus as two model systems.