Current research: Mechanistic Analysis of the Pyridoxal-5’-Phosphate-Dependent Decarboxylative Aldolase, UstD
Aldolases are the premier C–C bond-forming enzymes in nature. The decarboxylative aldolase, UstD, has recently found its place as a biocatalyst for the synthesis of g-hydroxy non-canonical amino acids. Previous engineering efforts have broadened the scope of UstD, but its synthetic utility still remains limited to activated carbonyl compounds. In addition, the proposed mechanism lacks extensive study, leaving the molecular determinants of reactivity vague and speculative. My work aims to explore the molecular determinants of UstD reactivity by characterizing the promiscuity of previously evolved variants and probing the bond-forming and bond-breaking steps of the mechanism. This mechanistic information will be leveraged in the rational design of UstD for future engineering of new reactivity beyond aldol chemistry with carbonyl compounds, widening the scope of C–C bond-forming reactions. This research will provide additional ways to synthesize non-canonical amino acids that are otherwise difficult to access and make UstD a more broadly useful biocatalyst.