Kawasaki Takashi, Kuzuyama Tomohisa, Furihata Kazuo, Itoh Nobuya, Seto Haruo, Dairi Tohru
Biotechnology Research Center, Toyama Prefectural University, Toyama 939-0398, Japan.
J Antibiot (Tokyo). 2003 Nov;56(11):957-66. doi: 10.7164/antibiotics.56.957.
Most Streptomyces strains are equipped with only the 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway for the formation of isopentenyl diphosphate. In addition to this pathway, some Strepromyces strains have the mevalonate pathway to produce terpenoid antibiotics. We have previously shown that a gene cluster for biosynthesis of terpentecin, a diterpene antibiotic, was located in adjacent the mevalonate pathway gene cluster. In this study, a mevalonate pathway gene cluster was cloned from Actinoplanes sp. strain A40644, an isoprenoid antibiotic BE-40644 producer, to examine whether the mevalonate pathway genes and isoprenoid biosynthetic genes are clustered in genomic DNA. By sequencing flanking regions a probable BE-40644 biosynthetic gene cluster was found in the downstream region of the mevalonate pathway gene cluster. Heterologous expression of a 9-kb fragment confirmed that a set of the BE-40644 biosynthetic genes was involved in the fragment. This result suggested that the presence of the mevalonate pathway might be a good landmark to detect the production of isoprenoid compounds by actinomycetes.
大多数链霉菌菌株仅通过2-C-甲基-D-赤藓糖醇4-磷酸（MEP）途径来合成异戊烯基二磷酸。除了该途径外，一些链霉菌菌株还具有甲羟戊酸途径来产生萜类抗生素。我们之前已经表明，二萜类抗生素terpentecin的生物合成基因簇位于甲羟戊酸途径基因簇附近。在本研究中，从类异戊二烯抗生素BE-40644的产生菌——游动放线菌属菌株A40644中克隆了甲羟戊酸途径基因簇，以研究甲羟戊酸途径基因和类异戊二烯生物合成基因在基因组DNA中是否成簇。通过对侧翼区域进行测序，在甲羟戊酸途径基因簇的下游区域发现了一个可能的BE-40644生物合成基因簇。一个9 kb片段的异源表达证实该片段中包含一组BE-40644生物合成基因。这一结果表明，甲羟戊酸途径的存在可能是检测放线菌产生类异戊二烯化合物的一个良好标志。
