10.1021/jacs.8b02769.s001 Hayama Tsutsumi Hayama Tsutsumi Yohei Katsuyama Yohei Katsuyama Miho Izumikawa Miho Izumikawa Motoki Takagi Motoki Takagi Manabu Fujie Manabu Fujie Noriyuki Satoh Noriyuki Satoh Kazuo Shin-ya Kazuo Shin-ya Yasuo Ohnishi Yasuo Ohnishi Unprecedented Cyclization Catalyzed by a Cytochrome P450 in Benzastatin Biosynthesis American Chemical Society 2018 cytochrome P 450 nitrene transferase cyclization enzyme RI tetrahydroquinoline scaffolds acid benzastatin biosynthetic gene cluster geranylated p Unprecedented Cyclization Catalyzed indoline Benzastatin Biosynthesis Benzastatins cytochrome P 450 Cytochrome P 450 BezE catalyzes elimination 2018-05-02 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/Unprecedented_Cyclization_Catalyzed_by_a_Cytochrome_P450_in_Benzastatin_Biosynthesis/6294287 Benzastatins have unique structures probably derived from geranylated <i>p</i>-aminobenzoic acids. The indoline and tetrahydroquinoline scaffolds are presumably formed by cyclization of the geranyl moiety, but the cyclization mechanism was unknown. We studied the benzastatin biosynthetic gene cluster of <i>Streptomyces</i> sp. RI18; functions of the six enzymes encoded by it were analyzed by gene disruption in a heterologous host and in vitro enzyme assays. We propose the biosynthetic pathway for benzastatins in which a cytochrome P450 (BezE) is responsible for the cyclization of geranylated <i>p</i>-acetoxyaminobenzoic acids; BezE catalyzes elimination of acetic acid to form an iron nitrenoid, nitrene transfer to form an aziridine ring, and nucleophilic addition of hydroxide ion to C-10 and chloride ion to C-9 to generate the indoline and tetrahydroquinoline scaffolds, respectively. Discovery of this enzyme, which should be termed cytochrome P450 nitrene transferase, provides an important insight into the functional diversity of cytochrome P450.