标题：Biosynthesis and Heterologous Production of Vioprolides: Rational Biosynthetic Engineering and Unprecedented 4-Methylazetidine-carboxylic Acid Formation
作者：Yan, Fu; Auerbach, David; Chai, Yi; Keller, Lena; Tu, Qiang; Huettel, Stephan; Glemser, Amelie; Grab, Hanusch A.; Bach, Thorsten; Zh 更多 作者机构：[Yan, Fu; Auerbach, David; Chai, Yi; Keller, Lena; Tu, Qiang; Mueller, Rolf] Saarland Univ, Helmholtz Ctr Infect Res, Helmholtz Inst Pharmaceut Res Sa 更多
通讯作者地址：[Muller, R]Saarland Univ, Helmholtz Ctr Infect Res, Helmholtz Inst Pharmaceut Res Saarland HIPS, Campus Bldg E8-1, D-66123 Saarbrucken, Germany;[Mulle 更多
来源：ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
关键词：azetidine; biosynthesis; heterologous expression; natural products;; vioprolide
摘要：Vioprolides are a promising class of anticancer and antifungal lead compounds produced by the myxobacterium Cystobacter violaceus Cbvi35. Previously nothing had been reported about their biosynthesis, including the origin of the unusual 4-methylazetidinecarboxylic acid (MAZ) moiety. We describe the vioprolide biosynthetic gene cluster and solve the production obstacle by expression in three heterologous hosts. Starting from unstable production in the wild type at the single-digit mgL(-1) scale, we developed a stable host that eventually allowed for yields of up to half a gram per liter in fermenters. Gene inactivations coupled with isotope feeding studies identified an S-adenosylmethionine (SAM)-dependent enzyme and a methyltransferase as being responsible for the generation of the MAZ building block by a proposed mechanism unprecedented in bacteria. Furthermore, nonnatural vioprolide derivatives were generated via rational genetic engineering.