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Publication Abstract from PubMed

Microbial epoxide hydrolases, cis-epoxysuccinate hydrolases (CESHs), have been utilized for commercial production of enantiomerically pure L(+)- and D(-)-tartaric acids for decades. However, the stereo-catalytic mechanism of CESH producing L(+)-tartaric acid (CESH[L]) remains unclear. Herein, the crystal structures of two CESH[L]s in ligand-free, product-complexed, and catalytic intermediate forms were determined. These structures revealed the unique specific binding mode for the mirror-symmetric substrate, an active catalytic triad consisting of Asp-His-Glu, and an arginine providing a proton to the oxirane oxygen to facilitate the epoxide ring-opening reaction, which has been pursued for decades. These results provide the structural basis for the rational engineering of these industrial biocatalysts.

Deciphering the stereo-specific catalytic mechanisms of cis-epoxysuccinate hydrolases producing L(+)-tartaric acid.,Dong S, Xuan J, Feng Y, Cui Q J Biol Chem. 2024 Feb;300(2):105635. doi: 10.1016/j.jbc.2024.105635. Epub 2024 , Jan 8. PMID:38199576^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.