Samoĭlenko V A, Syrchin S A, Tsymbal N V, Mendzhul M I
Mikrobiol Z. 2004 Jul-Aug;66(4):34-42.
Three vector constructions--pSTS2, pSTS3 and pSTS4 have been obtained on the basis of the standard vector for Escherichia coli pBR 322, cyanobacterial plasmid pSM1 and its separate fragments. The structure of pSTS4, carrying the full-size plasmid pSM1 (cloned by the restriction site Hpa II), replicated both in the cells of E. coli and in the cells-transconjugants of the trichomal cyanobacterium Plectonema boryanum. Under these conditions resistance of P. boryanum cells to ampicillin increases three orders, and to tetracyclin--50 times. Structural integrity of pSTS4 is stably supported in conjugates during seven successive passages (time of the experiment) and preserved the transforming capacity in respect of the cells of E. coli. It is supposed that pSTS4 is a shuttle-vector with two active origins of replication; one of them provides for the replication of pSTS4 in E. coli cells, another--in P. boryanum cells.
基于大肠杆菌pBR 322的标准载体、蓝藻质粒pSM1及其单独片段，已获得三种载体构建体——pSTS2、pSTS3和pSTS4。携带全长质粒pSM1（通过限制性酶切位点Hpa II克隆）的pSTS4的结构，在大肠杆菌细胞和丝状蓝藻波氏席藻的细胞转接合子中均可复制。在这些条件下，波氏席藻细胞对氨苄青霉素的抗性增加三个数量级，对四环素的抗性增加50倍。在连续七代传代（实验时间）过程中，pSTS4的结构完整性在接合体中得到稳定维持，并保留了对大肠杆菌细胞的转化能力。推测pSTS4是一种具有两个活性复制起点的穿梭载体；其中一个负责pSTS4在大肠杆菌细胞中的复制，另一个负责在波氏席藻细胞中的复制。
