Genetic, biosynthetic and functional versatility of polyketide synthases

Polyketide synthases (PKSs) are multi-functional enzymes that exhibit a great deal of diversity in their biosynthetic mechanism. This versatility allows them to influence an organism's biology in varied ways. Although many polyketides have been identified till now, and their biosynthetic pathways characterized, many more are waiting to be uncovered. With genome sequences of many organisms available now, the repository of putative pks genes is growing and so is the complexity involved in determining their possible products and functional roles in nature. Needless to say, efforts at the identification of novel products and pathways require a systematic, multi-pronged approach. In this review we discuss the growth of the PKS field and how it has undergone a pronounced transformation. We examine the various ways by which nature introduces variations in the products formed by these enzymes in different organisms to suit their biology. We further examine the different tools employed to crack the 'PKS puzzle' and how the future looks for research in this field.