IS1-mediated tandem duplication of plasmid pBR322. Dependence on recA and on DNA polymerase I.
IS1-mediated tandem duplication of plasmid pBR322. Dependence on recA and on DNA polymerase I.
复制标题
IS1 介导的质粒 pBR322 的串联复制。
DOI：
10.1016/s0022-2836(83)80249-6
复制
发表时间：
1983
影响因子：
5.6
通讯作者：
Galas,DJ
中科院分区：
文献类型：
--
作者：
Chandler,M;Galas,DJ
转座元件介导的共轭质粒pOX38:: tn9与pBR322的融合产生了由每个质粒单个拷贝组成的协整体，以及携带单个pOX38拷贝但串联多个pBR322拷贝的协整体。这些质粒被直接重复的转座因子拷贝分开。我们在这里证明了这种多聚体可以由单体协整产生，可能是通过两侧Tn9（IS1）元素之间的不均匀交叉产生的。因此，它们的出现不一定与最初的移位（融合）事件有关。我们的研究表明，复制过程强烈依赖于大肠杆菌的同源重组系统，因为我们的方法在reca -菌株中检测不到。它还强烈依赖于细胞中功能性DNA聚合酶I的存在。因此，这种复制的主要途径似乎依赖于同源重组系统和复制片段的复制。
Transposable-element-mediated fusion of the conjugal plasmid pOX38::Tn9with pBR322 results in the appearance of cointegrates composed of a single copy of each plasmid, and cointegrates which carry a single copy of pOX38 but multiple tandem copies of pBR322. These plasmids are separated by directly repeated copies of the transposable element. We demonstrate here that such multimers can be generated from monomeric cointegrates, probably by unequal crossing over between the flanking Tn9(IS1) elements. Their appearance is thus not necessarily associated with the original transposition (fusion) event. Our study demonstrates that the process of duplication is strongly dependent on the homologous recombination system ofEscherichia coli, since it is undetectable by our methods inrecA−strains. It is also strongly dependent on the presence of a functional DNA polymerase I in the cell. The major pathway(s) for this duplication thus appears to rely on both the homologous recombination system and the replication of the duplicated segment.