Glucose-1-phosphate thymidylyltransferase promotes the production of 3-O-α-mycarosylerythronolide B in Streptomyces coelicolor

The main objective of this study was to produce erythronolide B (EB) and 3-O-α-mycarosylerythronolide B (MEB) in Streptomyces coelicolor and enhance the MEB production by expressing the glucose-1-phosphate thymidylyltransferase (RfbA). We expressed eryF and eryB genes (eryBII, eryBIII, eryBIV, eryBV, eryBVI, and eryBVII) to produce EB and MEB. The expression was confirmed by quantitative real-time polymerase chain reaction. Furthermore, the MEB's production was improved by more than 100-fold by expressing an enzyme, RfbA, which is absent from the erythromycin gene cluster, to promote the biosynthesis of TDP-L-mycarose. We discuss the feasibility of alternative Streptomyces species for erythromycin production based on the presence or absence of RfbA. The RbfA enzyme from Saccharopolyspora erythraea was expressed in S. coelicolor M1152 along with the MEB biosynthesis pathway, resulting in a large increase in MEB production (>100-fold).