6JQH

Crystal structure of MaDA

Summary for 6JQH

• Entry DOI: 10.2210/pdb6jqh/pdb
• Descriptor: MaDA, FLAVIN-ADENINE DINUCLEOTIDE (3 entities in total)
• Functional Keywords: diels-alder reaction, fad-dependent enzyme, plant protein
• Biological source: Morus alba
• Total number of polymer chains: 2
• Total formula weight: 118542.71

Authors

Du, X.X.,Lei, X.G. (deposition date: 2019-03-31, release date: 2020-04-08, Last modification date: 2024-10-23)

Primary citation

Gao, L.,Su, C.,Du, X.,Wang, R.,Chen, S.,Zhou, Y.,Liu, C.,Liu, X.,Tian, R.,Zhang, L.,Xie, K.,Chen, S.,Guo, Q.,Guo, L.,Hano, Y.,Shimazaki, M.,Minami, A.,Oikawa, H.,Huang, N.,Houk, K.N.,Huang, L.,Dai, J.,Lei, X.
FAD-dependent enzyme-catalysed intermolecular [4+2] cycloaddition in natural product biosynthesis.
Nat.Chem., 12:620-628, 2020

PubMed Abstract: The Diels-Alder reaction is one of the most powerful and widely used methods in synthetic chemistry for the stereospecific construction of carbon-carbon bonds. Despite the importance of Diels-Alder reactions in the biosynthesis of numerous secondary metabolites, no naturally occurring stand-alone Diels-Alderase has been demonstrated to catalyse intermolecular Diels-Alder transformations. Here we report a flavin adenine dinucleotide-dependent enzyme, Morus alba Diels-Alderase (MaDA), from Morus cell cultures, that catalyses an intermolecular [4+2] cycloaddition to produce the natural isoprenylated flavonoid chalcomoracin with a high efficiency and enantioselectivity. Density functional theory calculations and preliminary measurements of the kinetic isotope effects establish a concerted but asynchronous pericyclic pathway. Structure-guided mutagenesis and docking studies demonstrate the interactions of MaDA with the diene and dienophile to catalyse the [4+2] cycloaddition. MaDA exhibits a substrate promiscuity towards both dienes and dienophiles, which enables the expedient syntheses of structurally diverse natural products. We also report a biosynthetic intermediate probe (BIP)-based target identification strategy used to discover MaDA.

PubMed: 32451436
DOI: 10.1038/s41557-020-0467-7

Experimental method

X-RAY DIFFRACTION (2.303 Å)