Zhang, YujunYujunZhangMa, Cheng-WeiCheng-WeiMaDischert, WandaWandaDischertSoucaille, PhilippePhilippeSoucailleZeng, An-PingAn-PingZeng2020-02-072020-02-072019-09-01Biotechnology Journal 9 (14): 1900003 (2019-09-01)http://hdl.handle.net/11420/4792Phosphoserine aminotransferase (SerC) from Escherichia coli (E. coli) MG1655 is engineered to catalyze the deamination of homoserine to 4-hydroxy-2-ketobutyrate, a key reaction in producing 1,3-propanediol (1,3-PDO) from glucose in a novel glycerol-independent metabolic pathway. To this end, a computation-based rational approach is used to change the substrate specificity of SerC from l-phosphoserine to l-homoserine. In this approach, molecular dynamics simulations and virtual screening are combined to predict mutation sites. The enzyme activity of the best mutant, SerCR42W/R77W, is successfully improved by 4.2-fold in comparison to the wild type when l-homoserine is used as the substrate, while its activity toward the natural substrate l-phosphoserine is completely deactivated. To validate the effects of the mutant on 1,3-PDO production, the “homoserine to 1,3-PDO” pathway is constructed in E. coli by coexpression of SerCR42W/R77W with pyruvate decarboxylase and alcohol dehydrogenase. The resulting mutant strain achieves the production of 3.03 g L−1 1,3-PDO in fed-batch fermentation, which is 13-fold higher than the wild-type strain and represents an important step forward to realize the promise of the glycerol-independent synthetic pathway for 1,3-PDO production from glucose.de1860-6768201991,3-Propanediolhomoserinephosphoserine aminotransferaseprotein engineeringJournal Article10.1002/biot.201900003Other