Reprogramming One-Carbon Metabolic Pathways To Decouple l -Serine Catabolism from Cell Growth in Corynebacterium glutamicum

作者：Yun Zhang, Xiuling Shang, Shujuan Lai, Yu Zhang, Qitiao Hu, Xin Chai, Bo Wang, Shuwen Liu, Tingyi Wen · 发表于：ACS Synthetic Biology · 年份：2018 · DOI：10.1021/acssynbio.7b00373 · 被引用次数：26 · 研究领域：Microbial Metabolic Engineering and Bioproduction、Amino Acid Enzymes and Metabolism、Enzyme Structure and Function

l -Serine, the principal one-carbon source for DNA biosynthesis, is difficult for microorganisms to accumulate due to the coupling of l -serine catabolism and microbial growth. Here, we reprogrammed the one-carbon unit metabolic pathways in Corynebacterium glutamicum to decouple l -serine catabolism from cell growth. In silico model-based simulation showed a negative influence on glyA -encoding serine hydroxymethyltransferase flux with l -serine productivity. Attenuation of glyA transcription resulted in increased l -serine accumulation, and a decrease in purine pools, poor growth and longer cell shapes. The gcvTHP -encoded glycine cleavage (Gcv) system from Escherichia coli was introduced into C. glutamicum, allowing glycine-derived 13 CH 2 to be assimilated into intracellular purine synthesis, which resulted in an increased amount of one-carbon units. Gcv introduction not only restored cell viability and morphology but also increased l -serine accumulation. Moreover, comparative proteomic analysis indicated that abundance changes of the enzymes involved in one-carbon unit cycles might be responsible for maintaining one-carbon unit homeostasis. Reprogramming of the one-carbon metabolic pathways allowed cells to reach a comparable growth rate to accumulate 13.21 g/L l -serine by fed-batch fermentation in minimal medium. This novel strategy provides new insights into the regulation of cellular properties and essential metabolite accumulation by introducing an extrinsic pathway...