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

利用黄酮特异性异戊烯基转移酶SfN 8DT-1从苦参培养细胞中克隆了第一个黄酮特异性异戊烯基转移酶SfG 6DT和第一个查耳酮特异性异戊烯基转移酶SfiLDT。它们都具有9个跨膜α-螺旋和质体靶向信号，通过系统发育分析证明它们都属于维生素E生物合成的异戊烯基转移酶家族。此外，还发现了一种参与大豆植保素生物合成的新酶GmG 4DT。除了豆科植物，类黄酮异戊二烯基转移酶也已在血桐（大戟科）中分离。通过构建SfN 8DT和SfG 6DT的串联嵌合酶，确定了SfN 8DT和SfG 6DT的底物识别决定区。此外，使用这些酶基因的代谢工程已经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.