Peh GuangRong, Tay Terence, Tan Lee Ling, Tiong Elaine, Bi Jiawu, Goh Yi Ling, Ye Suming, Lin Fu, Tan Cheryl Jia Xin, Tan Yong Zi, Wong Joel, Zhao Huimin, Wong Fong Tian, Ang Ee Lui, Lim Yee Hwee
Institute of Sustainability for Chemicals, Energy and Environment (ISCE2), Agency for Science, Technology and Research (A*STAR), Singapore, Republic of Singapore.
Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology and Research (A*STAR), Singapore, Republic of Singapore.
Commun Chem. 2024 Jan 5;7(1):7. doi: 10.1038/s42004-023-01083-1.
Halogenation of pyrrole requires strong electrophilic reagents and often leads to undesired polyhalogenated products. Biocatalytic halogenation is a highly attractive approach given its chemoselectivity and benign reaction conditions. While there are several reports of enzymatic phenol and indole halogenation in organic synthesis, corresponding reports on enzymatic pyrrole halogenation have been lacking. Here we describe the in vitro functional and structural characterization of PrnC, a flavin-dependent halogenase that can act on free-standing pyrroles. Computational modeling and site mutagenesis studies identified three key residues in the catalytic pocket. A moderate resolution map using single-particle cryogenic electron microscopy reveals PrnC to be a dimer. This native PrnC can halogenate a library of structurally diverse pyrrolic heterocycles in a site-selective manner and be applied in the chemoenzymatic synthesis of a chlorinated analog of the agrochemical fungicide Fludioxonil.
吡咯的卤化反应需要强亲电试剂，并且常常会生成不想要的多卤化产物。生物催化卤化反应因其化学选择性和温和的反应条件而成为一种极具吸引力的方法。虽然在有机合成中已有多篇关于酶促苯酚和吲哚卤化反应的报道，但关于酶促吡咯卤化反应的相应报道却一直缺乏。在此，我们描述了PrnC的体外功能和结构特征，PrnC是一种黄素依赖性卤化酶，可作用于游离的吡咯。计算建模和定点诱变研究确定了催化口袋中的三个关键残基。使用单颗粒低温电子显微镜获得的中等分辨率图谱显示PrnC为二聚体。这种天然的PrnC能够以位点选择性的方式卤化一系列结构多样的吡咯杂环，并可应用于农用化学杀菌剂氟啶胺的氯化类似物的化学酶促合成。
