Highly Efficient Biosynthesis of O-(3-Chloro-2-propenyl)hydroxylamine through Structure-Guided Engineering of Deacetylase

Clethodim is a widely utilized herbicide whose production depends on O-(3-chloro-2-propenyl)hydroxylamine (OCH) as a key intermediate. Enzymatic synthesis of OCH via deacetylases presents a sustainable alternative to traditional chemical methods. However, its industrial application is limited by low catalytic efficiency and narrow substrate specificity. In this study, to enhance the enzymatic deacetylation activity of native enzymes toward the non-natural substrate N-[(E)-3-chloroprop-2-enoxy]acetamide (NECA), we implement a structure-guided partition engineering strategy, systematically partitioning the enzyme into distinct regions for targeted modifications. The optimized variant EcDeac^{Y330A-C331N–H355Y} exhibited a 53-fold improvement in catalytic efficiency. Moreover, the engineered deacetylase displayed broadened substrate specificity. Molecular dynamics simulations revealed that these improvements stemmed from optimized substrate interactions, reduced spatial constraints, and improved hydrophilicity. This study demonstrates the positive impact on industrial OCH synthesis and confirms the speed and effectiveness of the partition engineering modification strategy.