In vitro analysis of type II polyketide synthase

Bacterial type II polyketide synthases (PKSs) are responsible for the biosynthesis of therapeutically important aromatic polyketides, including daunorubicin and tetracycline. Discovery and cloning of the type II, actinorhodin biosynthetic gene cluster from Streptomyces coelicolor marked the beginning of a new era in natural product biosynthesis. While genetics has played an indispensable role in understanding the programming rules of this unique family of natural product biosynthetic pathways, in vitro reconstitution and characterization of individual protein components have provided important insights into their mechanisms and specificities. In this chapter, we will provide an overview of in vitro analysis of type II PKSs in recent years. We will first describe the expression and purification of individual type II PKS components from different sources. This will be followed by a detailed description of the most commonly employed assays used to study different components of the type II PKSs.