The Catalytic Mechanism of a Natural Diels-Alderase Revealed in Molecular Detail.
Byrne, M.J., Lees, N.R., Han, L.C., van der Kamp, M.W., Mulholland, A.J., Stach, J.E., Willis, C.L., Race, P.R.(2016) J Am Chem Soc 138: 6095-6098
- PubMed: 27140661 
- DOI: https://doi.org/10.1021/jacs.6b00232
- Primary Citation of Related Structures:  
5DYQ, 5DYV - PubMed Abstract: 
The Diels-Alder reaction, a [4 + 2] cycloaddition of a conjugated diene to a dienophile, is one of the most powerful reactions in synthetic chemistry. Biocatalysts capable of unlocking new and efficient Diels-Alder reactions would have major impact. Here we present a molecular-level description of the reaction mechanism of the spirotetronate cyclase AbyU, an enzyme shown here to be a bona fide natural Diels-Alderase. Using enzyme assays, X-ray crystal structures, and simulations of the reaction in the enzyme, we reveal how linear substrate chains are contorted within the AbyU active site to facilitate a transannular pericyclic reaction. This study provides compelling evidence for the existence of a natural enzyme evolved to catalyze a Diels-Alder reaction and shows how catalysis is achieved.
Organizational Affiliation: 
School of Biochemistry, Biomedical Sciences Building, University of Bristol , University Walk, Bristol BS8 1TD, United Kingdom.