Macrolactonization catalyzed by the terminal thioesterase domain of the nonribosomal peptide synthetase responsible for lichenysin biosynthesis

The excised terminal thioesterase of the lichenysin nonribosomal peptide synthetase was found to be a highly efficient and versatile enzyme. Its activity strictly requires the R configuration of the β-hydroxy fatty acid and the side chains of aspartate-5 and isoleucine-7, but tolerates changes in five other residues of the substrate. Characterization of this enzyme facilitates future effort to engineer the lichenysin synthetase for biotechnological applications.