Structural and Biochemical Studies of a Biocatalyst for the Enzymatic Production of Wax Esters

Wax esters are high-value products whose enzymatic synthesis is of increasing biotechnological interest. The fabrication of cell factories that mass produce wax esters may provide a facile route toward a sustainable, and environmentally friendly, approach to a large-scale process for this commodity chemical. An expedient route for wax ester biocatalysis may be facilitated by the action of enzymes termed wax ester synthases/diacylglycerol acyltransferases (WS/DGAT), which produce wax esters using fatty acids and alcohols as a precursor. In this work, we report the structure for a member of the WS/DGAT superfamily. The structural data in conjunction with bioinformatics and mutational analyses allowed us to identify the substrate-binding pockets, as well as residues that may be important for catalysis. Using this information as a guide, we generated a mutant with preference toward shorter acyl substrates. This study demonstrates the efficacy of a structure-guided engineering effort toward a WS/DGAT variant with preference toward wax esters of desired lengths.