One-Pot Chemoenzymatic Synthesis of Arsinothricin and the Mechanistic Insights into the Noncanonical Radical SAM Enzyme ArsL

Arsinothricin (AST) is a broad-spectrum arsenic-containing antibiotic with promising pharmaceutical properties. In this study, we report the one-pot chemoenzymatic synthesis of AST starting from methylarsenate, a commonly used agricultural herbicide. Although a single point mutation in the C-terminal region of ArsL completely abolished its activity toward the natural substrate inorganic arsenite, this mutation unexpectedly enhanced its activity toward methylarsenate by over 50-fold, enabling subgram scale production of AST in a cell-free system. These findings offer valuable mechanistic insights into ArsL and highlight the significant potential of manipulating the radical SAM superfamily enzymes in synthetic applications.