Matsumoto Yuki, Ito Yoichiro, Tsuru Saburo, Ying Bei-Wen, Yomo Tetsuya
Department of Bioinformatics Engineering, Graduate School of Information Science and Technology, Osaka University, 1-5 Yamadaoka, Suita, Osaka 565-0871, Japan.
J Biomed Biotechnol. 2011;2011:489265. doi: 10.1155/2011/489265. Epub 2011 Nov 28.
A synthetic dual-function operon with a bistable structure was designed and successfully integrated into the bacterial genome. Bistability was generated by the mutual inhibitory structure comprised of the promoters P(tet) and P(lac) and the repressors LacI and TetR. Dual function essential for cell growth was introduced by replacing the genes (i.e., hisC and leuB) encoding proteins involved in the biosynthesis of histidine and leucine from their native chromosomal locations to the synthetic operon. Both colony formation and population dynamics of the cells carrying this operon showed that the cells survived starvation and the newly formed population transited between the two stable states, representing the induced hisC and leuB levels, in accordance with the nutritional status. The results strongly suggested that the synthetic design of proto-operons sensitive to external perturbations is practical and functional in native cells.
设计了一种具有双稳态结构的合成双功能操纵子，并成功整合到细菌基因组中。双稳态由启动子P(tet)和P(lac)以及阻遏物LacI和TetR组成的相互抑制结构产生。通过将编码参与组氨酸和亮氨酸生物合成的蛋白质的基因（即hisC和leuB）从其天然染色体位置替换到合成操纵子中，引入了对细胞生长至关重要的双功能。携带该操纵子的细胞的集落形成和群体动态均表明，细胞在饥饿状态下存活，并且新形成的群体根据营养状况在两种稳定状态之间转变，这两种稳定状态代表诱导的hisC和leuB水平。结果有力地表明，对外部扰动敏感的原操纵子的合成设计在天然细胞中是实用且有效的。
