The cytochrome P450 catalyzing C-S bond formation in S-heterocyclization of chuangxinmycin biosynthesis.
The cytochrome P450 catalyzing C-S bond formation in S-heterocyclization of chuangxinmycin biosynthesis.
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DOI：
10.1002/anie.202015814
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发表时间：
2021-04
影响因子：
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通讯作者：
Yu-zhan Shi;Zhibo Jiang;Xiaowen Hu;Xiaomin Hu;Renjie Gu;Bingya Jiang;Lijie Zuo;Xingxing Li;Hongmin Sun;Cong Zhang;Li-fei Wang;Linzhuan Wu;Bin Hong
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文献类型：
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作者：
Yu-zhan Shi;Zhibo Jiang;Xiaowen Hu;Xiaomin Hu;Renjie Gu;Bingya Jiang;Lijie Zuo;Xingxing Li;Hongmin Sun;Cong Zhang;Li-fei Wang;Linzhuan Wu;Bin Hong
微生物含硫次级代谢产物具有多种生物活性，其生物合成代谢中的C-S键形成机制尚不清楚。在此，我们对细胞色素P450单加氧酶CxnD的遗传、生化和结构特征进行了研究。该酶在S生物合成中具有C-S键形成活性。体内和体外分析表明，CxnD从L-色氨酸衍生的硫醇中间体中生成了吲哚稠合的二氢噻喃骨架。此外，CxnD与底物类似物的X射线晶体结构和基于结构的诱变揭示了底物结合模式的密切细节。提出了CxnD由底物吲哚基团上的亚氨基氢原子或电子被抽提引发的自由基反应机理，为P450在创心霉素生物合成中分子内C(Sp2)-H硫基化反应提供了有价值的分子基础。
Microbial sulfur-containing secondary metabolites show various biological activities and the C-S bond-forming in their biosynthetic metabolism has not been thoroughly understood. Here, we present genetic, biochemical and structural characterization of a cytochrome P450 monooxygenase CxnD exhibiting C-S bond forming activity in S-heterocyclization of chuangxinmycin biosynthesis. In vivo and in vitro analyses demonstrated that CxnD generated an indole-fused dihydrothiopyran skeleton from a L-Trp-derived thiol intermediate. Furthermore, X-ray crystal structure of CxnD in complex with a substrate analogue and structure-based mutagenesis revealed intimate details of the substrate binding mode. A radical mechanism initiated by abstraction of the imino hydrogen atom or an electron from indole group of the substrate was proposed for CxnD, which provided valuable insights into the molecular basis for the intra-molecular C(sp2)-H thiolation by the P450 in chuangxinmycin biosynthesis.