Multifactorial Control of Iteration Events in a Modular Polyketide Assembly Line

The poly-ketide synthases (PKSs) in charge of selecting, fusing, andprocessing the building blocks are organized into modulesthat consist of individual catalytic domains. Typically, there isa unidirectional progress of chain elongation, where eachdomainisonlyusedonceinthebiosynthesisofonepolyketidemolecule. Thus, for most synthases there is a strict colinearitybetween the number and architecture of the modules and thenumberofelongationsanddegreeofb-ketoprocessing.