Figure 1. The erythromycin PKS system. Erythromycin is synthesized as a polymer tethered to an assembly line of polyketide synthases (PKSs). It is then cyclized, and next, modified to its final structure. The pathway has three PKS polypeptides containing six modules and loading and releasing domains. The cyclized structure shown is not the complete molecule; other downstream enzymes are required to bring erythromycin to its final structure. Identical colors in different modules indicate similar enzymatic reactions. |
