Biosynthesis of spinosyn in Saccharopolyspora spinosa: synthesis of permethylated rhamnose and characterization of the functions of SpnH, Spnl, and SpnK

The catalytic properties of the spnH, spnI and spnK gene products are studied and their roles in the permethylation process of spinosyn A are validated in order to verify the functions of the rhamnose methyltransferases and also their coordination to achieve the desired level of methylation of rhamnose. The studies have shown that the completion of rhamnose permethylation is achieved by the proper control of the expression levels of the methyltransferase genes involved.