Cryptic Oxidative Transamination of Hydroxynaphthoquinone in Natural Product Biosynthesis
Cryptic Oxidative Transamination of Hydroxynaphthoquinone in Natural Product Biosynthesis
复制标题
DOI：
10.1021/jacs.1c13074
复制
发表时间：
2022-03-30
影响因子：
15
通讯作者：
Kuzuyama, Tomohisa
中科院分区：
文献类型：
--
作者：
Noguchi, Tomohiro;Isogai, Shota;Kuzuyama, Tomohisa
吡哆醛5 '-磷酸（PLP）依赖性酶是一组催化各种反应的多功能酶，但只有少数酶与O-2反应。在这里，我们报告了一个前所未有的PLP依赖性酶，NphE，催化转氨和双电子氧化使用O-2作为氧化剂。我们的深入分析表明，NphE转移的L-谷氨酸衍生的胺，1，3，6，8-四羟基萘衍生的mompain，形成8-氨基-flaviolin（8-AF）通过一个高度共轭的quinidine中间体，是与O-2反应。在NphE反应期间，O-2被还原以产生H2 O2。一个集成的技术，包括NphE结构预测AlphaFold v2.0和分子动力学模拟建议的O-2可访问的空腔。我们的体内结果表明，8-AF是1，3，6，8-四羟基萘衍生的不含氨基的部分萜类萘的真正生物合成中间体，这得到了定点突变的支持。这项研究清楚地建立了NphE反应产物8-AF作为一个共同的中间体与一个隐蔽的氨基生物合成的萜类-聚酮化合物混合天然产物。
Pyridoxal 5'-phosphate (PLP)-dependent enzymes are a group of versatile enzymes that catalyze various reactions, but only a small number of them react with O-2. Here, we report an unprecedented PLP-dependent enzyme, NphE, that catalyzes both transamination and two-electron oxidation using O-2 as an oxidant. Our intensive analysis reveals that NphE transfers the L-glutamatederived amine to 1,3,6,8-tetrahydroxynaphthalene-derived mompain to form 8-amino-flaviolin (8-AF) via a highly conjugated quinonoid intermediate that is reactive with O-2. During the NphE reaction, O-2 is reduced to yield H2O2. An integrated technique involving NphE structure prediction by AlphaFold v2.0 and molecular dynamics simulation suggested the O-2-accessible cavity. Our in vivo results demonstrated that 8-AF is a genuine biosynthetic intermediate for the 1,3,6,8-tetrahydroxynaphthalene-derived meroterpenoid naphterpin without an amino group, which was supported by site-directed mutagenesis. This study clearly establishes the NphE reaction product 8-AF as a common intermediate with a cryptic amino group for the biosynthesis of terpenoid-polyketide hybrid natural products.