1. Engineering Glucosamine-6-Phosphate Synthase to Achieve Efficient One-Step Biosynthesis of Glucosamine.
- Author
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Guan ZB, Deng XT, Zhang ZH, Xu GC, Cheng WL, Liao XR, and Cai YJ
- Subjects
- Molecular Docking Simulation, Fructose metabolism, Fructose chemistry, Fructose biosynthesis, Molecular Dynamics Simulation, Bacterial Proteins metabolism, Bacterial Proteins genetics, Bacterial Proteins chemistry, Catalytic Domain, Glucosamine biosynthesis, Glucosamine metabolism, Glucosamine chemistry, Glutamine-Fructose-6-Phosphate Transaminase (Isomerizing) metabolism, Glutamine-Fructose-6-Phosphate Transaminase (Isomerizing) genetics, Glutamine-Fructose-6-Phosphate Transaminase (Isomerizing) chemistry, Bacillus subtilis enzymology, Bacillus subtilis metabolism, Bacillus subtilis genetics, Protein Engineering
- Abstract
As an important functional monosaccharide, glucosamine (GlcN) is widely used in fields such as medicine, food nutrition, and health care. Here, we report a distinct GlcN biosynthesis method that utilizes engineered Bacillus subtilis glucosamine-6-phosphate synthase ( Bs GlmS) to convert D-fructose to directly generate GlcN. The best variant obtained by using a combinatorial active-site saturation test/iterative saturation mutagenesis (CAST/ISM) strategy was a quadruple mutant S596D/V597G/S347H/G299Q ( Bs GlmS-BK19), which has a catalytic activity 1736-fold that of the wild type toward D-fructose. Upon using mutant BK19 as a whole-cell catalyst, D-fructose was converted into GlcN with 65.32% conversion in 6 h, whereas the wild type only attained a conversion rate of 0.31% under the same conditions. Molecular docking and molecular dynamics simulations were implemented to provide insights into the mechanism underlying the enhanced activity of BK19. Importantly, the Bs GlmS-BK19 variant specifically catalyzes D-fructose without the need for phosphorylated substrates, representing a significant advancement in GlcN biosynthesis.
- Published
- 2024
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