Molecular Basis for Two Stereoselective Diels-Alderases that Produce Decalin Skeletons*.
Molecular Basis for Two Stereoselective Diels-Alderases that Produce Decalin Skeletons*.
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DOI：
10.1002/anie.202106186
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发表时间：
2021-10-04
期刊：
影响因子：
--
通讯作者：
Nagano S
中科院分区：
文献类型：
--
作者：
Fujiyama K;Kato N;Re S;Kinugasa K;Watanabe K;Takita R;Nogawa T;Hino T;Osada H;Sugita Y;Takahashi S;Nagano S
催化[4 + 2]环加成反应的酶在天然产物的生物合成中起着重要作用，因而受到人们的广泛关注。在这里，我们解决了一对十氢萘糖苷酶Fsa 2和Phm 7的X射线晶体结构，它们在HIV-1整合酶抑制剂木贼素及其立体化学相反物phomasetin的生物合成过程中催化分子内[4 + 2]环加成形成对映体十氢萘支架。使用分子动力学模拟和量子化学计算的计算建模表明，反应通过协同构象约束进行，确保过渡态样底物折叠及其通过特定蛋白质-底物相互作用的稳定性。定点诱变实验验证了结合模型。有趣的是，结合底物的灵活性在两种酶中有很大不同，这表明这些立体选择性反应背后的独特动力学调节机制。本文提出的反应机理加深了对这些酶如何工作的基本理解，也为创造人工酶提供了指导原则。强大的实验方法和计算的结合突出了立体选择性[4 + 2]环加成反应催化的一对十氢萘糖苷酶，Fsa2和Phm7，催化分子内环加成反应，形成对映体十氢萘支架的独特的分子机制。我们提出的机制将为酶促[4 + 2]环加成反应打开一个新的窗口。
Enzymes catalyzing [4+2] cycloaddition have attracted increasing attention because of their key roles in natural product biosynthesis. Here, we solved the X‐ray crystal structures of a pair of decalin synthases, Fsa2 and Phm7, that catalyze intramolecular [4+2] cycloadditions to form enantiomeric decalin scaffolds during biosynthesis of the HIV‐1 integrase inhibitor equisetin and its stereochemical opposite, phomasetin. Computational modeling, using molecular dynamics simulations as well as quantum chemical calculations, demonstrates that the reactions proceed through synergetic conformational constraints assuring transition state‐like substrates folds and their stabilization by specific protein‐substrate interactions. Site‐directed mutagenesis experiments verified the binding models. Intriguingly, the flexibility of bound substrates is largely different in two enzymes, suggesting the distinctive mechanism of dynamics regulation behind these stereoselective reactions. The proposed reaction mechanism herein deepens the basic understanding how these enzymes work but also provides a guiding principle to create artificial enzymes. Powerful combination of experimental methods and calculations highlights the distinct molecular mechanisms underlying stereoselective [4+2] cycloadditions catalyzed by a pair of decalin synthases, Fsa2 and Phm7, that catalyze intramolecular cycloadditions to form enantiomeric decalin scaffolds. Our proposed mechanism would open a new window on the enzymatic [4+2] cycloadditions.
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影响因子：
15
作者：
Li L;Yu P;Tang MC;Zou Y;Gao SS;Hung YS;Zhao M;Watanabe K;Houk KN;Tang Y
通讯作者：
Tang Y
影响因子：
15
作者：
Li L;Tang MC;Tang S;Gao S;Soliman S;Hang L;Xu W;Ye T;Watanabe K;Tang Y
通讯作者：
Tang Y
影响因子：
21.8
作者：
Dan, Qingyun;Newmister, Sean A.;Williams, Robert M.
通讯作者：
Williams, Robert M.
影响因子：
4.4
作者：
Kamiya, Motoshi;Sugita, Yuji
通讯作者：
Sugita, Yuji
影响因子：
5.2
作者：
Agatsuma, T;Akama, T;Kanda, Y
通讯作者：
Kanda, Y