Department of Agriculture, Faculty of Agriculture and, Graduate School of Science and Technology, Niigata University, 8050 Ikarashi-2, Niigata, 950-2181, Japan.
Chembiochem. 2020 Oct 15;21(20):2931-2938. doi: 10.1002/cbic.202000235. Epub 2020 Jul 14.
Comprehensive functional analyses of E-isoprenyl diphosphate synthases (E-IDSs) from nonpathogenic Mycobacterium vanbaalenii have been performed. Mv0992 and Mv1577 represent a nonaprenyl diphosphate (E-C ) synthase and a geranylgeranyl diphosphate (E-C ) synthase, respectively. Although Mv3536 was identified as an E-C synthase using a single enzyme, co-incubation of Mv3536 and Z-IDSs (Mv4662 and Mv3822) strongly suggested it releases an intermediate geranyl diphosphate (E-C ) during a continuous condensation reaction. Mv0992 and Mv3536 functions differed from those of the previously reported pathogenic Mycobacterium tuberculosis homologues Rv0562 and Rv2173, respectively. Re-analysis of Rv0562 and Rv2173 demonstrated that their functions were similar to those of Mv0992 and Mv3536 (Rv0562: E-C synthase; Rv2173: E-C synthase). The newly proposed functions of Rv0562 and Rv2173 would be in the biosynthesis of menaquinone and glycosyl carrier lipids essential for growth. Furthermore, a reduced allylic diphosphate could be used as the Z-IDS of the Mv3822 substrate, thereby introducing a potentially novel pathway of cyclic sesquarterpene biosynthesis.
已对非致病性分枝杆菌 vanbaalenii 的 E-异戊二烯二磷酸合酶（E-IDS）进行了综合功能分析。Mv0992 和 Mv1577 分别代表非单萜二磷酸合酶（E-C ）和香叶基香叶基二磷酸合酶（E-C ）。尽管 Mv3536 被鉴定为单酶的 E-C 合酶，但 Mv3536 与 Z-IDS（Mv4662 和 Mv3822）的共孵育强烈表明它在连续缩合反应中释放出一种中间的香叶基二磷酸（E-C ）。Mv0992 和 Mv3536 的功能与先前报道的致病性分枝杆菌结核同源物 Rv0562 和 Rv2173 不同。对 Rv0562 和 Rv2173 的重新分析表明，它们的功能类似于 Mv0992 和 Mv3536（Rv0562：E-C 合酶；Rv2173：E-C 合酶）。Rv0562 和 Rv2173 的新提出的功能将在甲萘醌和糖基载体脂质的生物合成中发挥作用，这些脂质对于生长是必不可少的。此外，减少的烯丙基二磷酸可以用作 Mv3822 底物的 Z-IDS，从而引入了一种潜在的新型环倍半萜生物合成途径。
