4o5t
From Proteopedia
Crystal structure of Diels-Alderase CE20 in complex with a product analog
Structural highlights
FunctionDFPA_LOLVU Biological function and substrate unknown. However, it is capable of acting on phosphorus anhydride bonds (such as phosphorus-halide and phosphorus-cyanide) in organophosphorus compounds (including nerve gases).[1] Publication Abstract from PubMedBy combining targeted mutagenesis, computational refinement, and directed evolution, a modestly active, computationally designed Diels-Alderase was converted into the most proficient biocatalyst for [4+2] cycloadditions known. The high stereoselectivity and minimal product inhibition of the evolved enzyme enabled preparative scale synthesis of a single product diastereomer. X-ray crystallography of the enzyme-product complex shows that the molecular changes introduced over the course of optimization, including addition of a lid structure, gradually reshaped the pocket for more effective substrate preorganization and transition state stabilization. The good overall agreement between the experimental structure and the original design model with respect to the orientations of both the bound product and the catalytic side chains contrasts with other computationally designed enzymes. Because design accuracy appears to correlate with scaffold rigidity, improved control over backbone conformation will likely be the key to future efforts to design more efficient enzymes for diverse chemical reactions. Impact of scaffold rigidity on the design and evolution of an artificial Diels-Alderase.,Preiswerk N, Beck T, Schulz JD, Milovnik P, Mayer C, Siegel JB, Baker D, Hilvert D Proc Natl Acad Sci U S A. 2014 May 20. pii: 201401073. PMID:24847076[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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