title: Introduction of two mutations into AroG increases phenylalanine production in Escherichia coli.
abstract: L-Phenylalanine is an important amino acid commercially, and therefore optimization of its manufacture is of interest. We constructed a range of mutant alleles of AroG, the enzyme involved in the first step of phenylalanine biosynthesis. Three single-site mutant alleles were constructed (aroG8, aroG15, and aroG29), which were then combined to generate three double-site aroG (fbr) mutant alleles (aroG8/15, aroG8/29, and aroG15/29). Enzymatic activity, feedback inhibition, and fermentation were analyzed in all of the mutants. All double-site mutants, except AroG15/29, showed higher enzymatic activity and greater resistance to feedback inhibition than their respective single-site mutants. The E. coli strain carrying the aroG8/15 allele produced a phenylalanine titer of 26.78 g/l, a 116 % improvement over the control phenylalanine overproducing strain (12.41 g/l). Our findings provide an effective method for modifying phenylalanine biosynthetic genes, which may be applied to optimize the commercial manufacture of phenylalanine.
authors: College of Agronomy, Shenyang Agricultural University, Shenyang, Liaoning, People's Republic of China, mnidr7@gmail.com.
authors: Rui
authors: R
authors: Ding
authors: Lifei
authors: L
authors: Liu
authors: Xuhui
authors: X
authors: Chen
authors: Zhenhai
authors: Z
authors: Cui
authors: Ao
authors: A
authors: Zhang
authors: Daming
authors: D
authors: Ren
authors: Lijun
authors: L
authors: Zhang
mesh_terms: D010723:3-Deoxy-7-Phosphoheptulonate Synthase / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism; D005285:Fermentation; D009154:Mutation; D010649:Phenylalanine / Q000096:biosynthesis*
chemical_list: D029968:Escherichia coli Proteins; D010649:Phenylalanine; D010723:3-Deoxy-7-Phosphoheptulonate Synthase