Molecular dissection of prenyltransferase family involved in flavonoid functionalization and the enzyme engineering

利用黄酮特异性戊烯基转移酶SfN8DT-1从苦豆子培养细胞中克隆出首个异黄酮特异性戊烯基转移酶SfG6DT和首个查尔酮特异性戊烯基转移酶SfiLDT。通过系统发育分析，证实这些类黄酮戊烯基转移酶均属于维生素E生物合成戊烯基转移酶家族。此外，还发现了一种参与大豆植物抗菌素生物合成的新酶GmG4DT。除豆科外，黄酮类戊烯基转移酶也被分离到大戟科植物中。通过在SfN8DT和SfG6DT之间制作序列嵌合酶，确定了一个底物识别的决定区域。此外，利用这些酶基因的代谢工程已在植物和细菌宿主中进行。

The first isoflavone-specific prenyltransferase SfG6DT and the first chalcone-specific one SfiLDT have been cloned from cultured cells of Sophora flavescens by utilizing flavone-specific prenyltransferase SfN8DT-1. Both have 9 transmembrane alpha-helices and plastid-targeting signal, and by phylogenetic analysis it was turned out that all those flavonoid prenyltransferase belong to prenyltransferase family for vitamin E biosynthesis. Moreover, a new enzyme GmG4DT involved in phytoalexin biosynthesis in soybean has been identified. Beyond Leguminosae, flavonioid prenyltransferases have been isolated in Macaranga tanarius(Euphorbiaceae), as well. By making serial chimeric enzyme between SfN8DT and SfG6DT, a determinant region for substrate recognition could be determined. Furthermore, metabolic engineering using those enzyme genes have been carried out in plant and bacterial hosts.