Precise precursor rebalancing for isoprenoids production by fine control of gapA expression in Escherichia coli

• Published in: Metabolic engineering Vol. 38; pp. 401 - 408
• Main Authors: Jung, Juyoung, Lim, Jae Hyung, Kim, Se Yeon, Im, Dae-Kyun, Seok, Joo Yeon, Lee, Seung-Jae V., Oh, Min-Kyu, Jung, Gyoo Yeol
• Format: Journal Article
• Language: English
• Published: Belgium Elsevier Inc 01.11.2016
• Subjects: Biosynthetic Pathways - genetics; Carotenoids - metabolism; Escherichia coli; Escherichia coli Proteins; G3P; gapA; Gene Expression Regulation, Bacterial - genetics; Gene Expression Regulation, Enzymologic - genetics; Genetic Enhancement - methods; Glyceraldehyde-3-Phosphate Dehydrogenases - genetics; Glyceraldehyde-3-Phosphate Dehydrogenases - metabolism; Isoprenoid; Lycopene; Metabolic Engineering - methods; Metabolic Networks and Pathways - genetics; ppsA; Precursor balancing; Terpenes - isolation & purification; Terpenes - metabolism; ppsA; gapA; Precursor balancing; Isoprenoid; G3P; Lycopene
• ISSN: 1096-7176; 1096-7184
• DOI: 10.1016/j.ymben.2016.10.003

Biosynthesis of isoprenoids via the 1-deoxy-D-xylulose-5-phosphate (DXP) pathway requires equimolar glyceraldehyde 3-phosphate and pyruvate to divert carbon flux toward the products of interest. Here, we demonstrate that precursor balancing is one of the critical steps for the production of isoprenoids in Escherichia coli. First, the implementation of the synthetic lycopene production pathway as a model system and the amplification of the native DXP pathway were accomplished using synthetic constitutive promoters and redesigned 5′-untranslated regions (5′-UTRs). Next, fine-controlled precursor balancing was investigated by tuning phosphoenolpyruvate synthase (PpsA) or glyceraldehyde 3-phosphate dehydrogenase (GAPDH). The results showed that tuning-down of gapA improved the specific lycopene content by 45% compared to the overexpression of ppsA. The specific lycopene content in the strains with down-regulated gapA increased by 97% compared to that in the parental strain. Our results indicate that gapA is the best target for precursor balancing to increase biosynthesis of isoprenoids. [Display omitted] •The effect of precursor balancing for the biosynthesis of isoprenoids was explored through fine-control of ppsA and gapA.•Precise down-regulation of gapA showed a better lycopene production than up-regulation of ppsA.•A novel target (gapA) to balance precursor pool for biosynthesis of isoprenoids was demonstrated for the first time.