Figure 2. Erythromycin chemobiosynthesis. As developed at Kosan, chemobiosynthesis allows synthetic intermediates to be loaded onto the erythromycin PKS system. The first ketosynthase (KS) in the system (marked X) was genetically inactivated in a Streptomyces strain, so that the monomer that attaches to the loading domain cannot be extended. When the bacteria are fed analogues of the products of the first module, they enter the PKS system at the KS of the second module and then proceed through the pathway. Structures of the new compounds emerging from the system are indicated. |
