The insufficient supply of sugar units is the key limitation for the biosynthesis of glycosylated products.The unusual sugar TDP-L-mycarose is initially attached to the C3 of the polyketide erythronolide B,resulting i...The insufficient supply of sugar units is the key limitation for the biosynthesis of glycosylated products.The unusual sugar TDP-L-mycarose is initially attached to the C3 of the polyketide erythronolide B,resulting in 3-O-α-mycarosylerythronolide B(MEB).Here,we present the de novo biosynthesis of MEB in Escherichia coli and improve its production using multi-strategy metabolic engineering.Firstly,by blocking precursor glucose-1-phosphate competing pathways,the MEB titer of triple knockout strain QC13 was significantly enhanced to 41.2 mg/L,9.8-fold to that produced by parental strain BAP230.Subsequently,the MEB production was further increased to 48.3 mg/L through overexpression of rfbA and rfbB.Moreover,the CRISPRi was implemented to promote the TDP-L-mycarose biosynthesis via repressing the glycolysis and TDP-L-rhamnose pathway.Our study paves the way for efficient production of erythromycins in E.coli and provides a promising platform that can be applied for biosynthesis of other glycosylated products with unusual sugars.展开更多
基金This study was financially supported by the National Key R&D Program of China(2018YFA0900600)the Program of Shanghai Academic Research Leader(20XD1404400)+4 种基金the Strategic Priority Research Program“Molecular mechanism of Plant Growth and Development”of CAS(XDB27020202)the National Natural Science Foundation of China(31670099)the Construction of the Registry and Database of Bioparts for Synthetic Biology of the Chinese Academy of Science(No.ZSYS-016)the International Partnership Program of Chinese Academy of Science(No.153D31KYSB20170121)the National Key Laboratory of Plant Molecular Genetics,SIPPE,CAS.
文摘The insufficient supply of sugar units is the key limitation for the biosynthesis of glycosylated products.The unusual sugar TDP-L-mycarose is initially attached to the C3 of the polyketide erythronolide B,resulting in 3-O-α-mycarosylerythronolide B(MEB).Here,we present the de novo biosynthesis of MEB in Escherichia coli and improve its production using multi-strategy metabolic engineering.Firstly,by blocking precursor glucose-1-phosphate competing pathways,the MEB titer of triple knockout strain QC13 was significantly enhanced to 41.2 mg/L,9.8-fold to that produced by parental strain BAP230.Subsequently,the MEB production was further increased to 48.3 mg/L through overexpression of rfbA and rfbB.Moreover,the CRISPRi was implemented to promote the TDP-L-mycarose biosynthesis via repressing the glycolysis and TDP-L-rhamnose pathway.Our study paves the way for efficient production of erythromycins in E.coli and provides a promising platform that can be applied for biosynthesis of other glycosylated products with unusual sugars.
