Metabolic engineering of polyketide biosynthesis.

Three elements came together during the past year to provide the opportunity to generate new polyketides. The first was the availability of cloned genes for several metabolic pathways; the second was a genetically defined host strain able to support the production of polyketides; and the third was the ability to modify specific genes and recombine genes from different pathways using recombinant DNA technology. These tools culminated in the rational design of new molecules and the biosynthesis of large numbers of new molecules using combinatorial biology.