Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo, 113-8657, Japan.
Angew Chem Int Ed Engl. 2021 Jul 12;60(29):15827-15831. doi: 10.1002/anie.202104644. Epub 2021 Jun 11.
Aziridine is a characteristically reactive molecule with increased bioactivity due to its strained ring structure. Here, we investigated the biosynthesis of 2-aminoisobutyric acid (AIB) in Penicillium, and successfully reconstituted the three-step biosynthesis from L-Val to AIB in vitro. This previously unknown aziridine formation pathway proceeded with the non-heme iron and α-ketoglutarate-dependent (Fe /αKG) oxygenase TqaL, followed by aziridine ring opening by the haloalkanoic acid dehalogenase (HAD)-type hydrolase TqaF, and subsequent oxidative decarboxylation by the NovR/CloR-like non-heme iron oxygenase TqaM. Furthermore, the X-ray crystal structure of the C-N bond forming Fe /αKG oxygenase TqaL was solved at 2.0 Å resolution. This work presents the first molecular basis for aziridine biogenesis, thereby expanding the catalytic repertoire of the Fe /αKG oxygenases. We also report the unique aziridine ring opening by a HAD-type hydrolase and the remarkable oxidative decarboxylation by a non-heme iron oxygenase to produce AIB.
氮丙啶是一种具有特征反应性的分子，由于其张力环结构，生物活性增加。在这里，我们研究了青霉素中 2-氨基异丁酸（AIB）的生物合成，并成功地在体外重新构建了从 L-Val 到 AIB 的三步生物合成。这个以前未知的氮丙啶形成途径涉及非血红素铁和 α-酮戊二酸依赖性（Fe/αKG）加氧酶 TqaL，随后由卤代烷酸脱卤酶（HAD）型水解酶 TqaF 打开氮丙啶环，然后由 NovR/CloR 样非血红素铁加氧酶 TqaM 进行氧化脱羧。此外，C-N 键形成的 Fe/αKG 加氧酶 TqaL 的 X 射线晶体结构以 2.0 Å 的分辨率解决。这项工作为氮丙啶生物合成提供了第一个分子基础，从而扩展了 Fe/αKG 加氧酶的催化谱。我们还报告了 HAD 型水解酶的独特氮丙啶开环和非血红素铁加氧酶的显著氧化脱羧作用，以产生 AIB。
