Oikawa Hideaki
Department of Chemistry, Faculty of Science, Hokkaido University.
Proc Jpn Acad Ser B Phys Biol Sci. 2020;96(9):420-430. doi: 10.2183/pjab.96.031.
While exploring phytotoxic metabolites from phytopathogenic fungi in the 1970s, we became interested in biosynthetic enzymes that catalyze Diels-Alder reactions involving biosynthesis of several phytotoxins that we isolated. Target enzymes were successfully characterized, and this triggered the identification of various Diels-Alderases in a recent decade. Through our Diels-Alderase project in 1990s, we recognized a highly efficient expression system of various biosynthetic genes with Aspergillus oryzae as a host. With the development of tools such as genomic data and bioinformatics analysis to identify biosynthetic gene clusters for natural products, we developed a highly reliable methodology such as hot spot knock-in to elucidate the biosynthetic pathways of representative fungal metabolites including phytotoxic substances. This methodology allows total biosynthesis of natural products and genome mining using silent biosynthetic gene clusters to obtain novel bioactive metabolites. Further applications of this technology are discussed.
20世纪70年代，在探索植物病原真菌的植物毒性代谢产物时，我们开始对催化狄尔斯-阿尔德反应的生物合成酶产生兴趣，这些反应涉及我们分离出的几种植物毒素的生物合成。目标酶被成功鉴定，这引发了近十年来各种狄尔斯-阿尔德酶的鉴定。通过我们在20世纪90年代的狄尔斯-阿尔德酶项目，我们认识到以米曲霉为宿主的各种生物合成基因的高效表达系统。随着用于鉴定天然产物生物合成基因簇的基因组数据和生物信息学分析等工具的发展，我们开发了一种高度可靠的方法，如热点敲入，以阐明包括植物毒性物质在内的代表性真菌代谢产物的生物合成途径。这种方法允许天然产物的全生物合成以及利用沉默生物合成基因簇进行基因组挖掘以获得新型生物活性代谢产物。本文还讨论了该技术的进一步应用。
