Replication of a plasmid lacking the normal site for initiation of one strand
Replication of a plasmid lacking the normal site for initiation of one strand
复制标题
DOI：
10.1128/jb.178.16.4870-4876.1996
复制
发表时间：
1996-08-01
影响因子：
3.2
通讯作者：
Meyer, RJ
中科院分区：
文献类型：
--
作者：
Becker, EC;Zhou, HS;Meyer, RJ
质粒R1162的复制起点包含合成每条DNA链的起始点。当其中一个位点(OriL)缺失时，相应链上的合成不再有效地由编码R1162的复制蛋白在体外启动，质粒不再稳定地保持在细胞中。然而，在体内，质粒双链分子的两条链与DNA合成模板的活性水平相似，新合成的每条链的副本以类似的速度并入子体分子。在起始区没有检测到Delta oriL链上的第二个强烈的起始点。Delta oril质粒会诱导SOS反应，即使在重组熟练的菌株中，这对于质粒的维持也是重要的。我们的结果表明，SOS诱导的宿主系统可以在没有一个起始点的情况下保持R1162衍生物。
The origin of replication of the plasmid R1162 contains an initiation site for the synthesis of each DNA strand. When one of these sites (oriL) is deleted, synthesis on the corresponding strand is no longer initiated efficiently in vitro by the R1162-encoded replication proteins, and the plasmid is no longer stably maintained in the cell. However, in vivo the two strands of the plasmid duplex molecule are active at a similar level as templates for DNA synthesis, and newly synthesized copies of each strand are incorporated into daughter molecules at a similar rate. No secondary, strong initiation sites on the Delta oriL, strand were detected in the region of the origin. The Delta oril plasmid induces the SOS response, and this is important for plasmid maintenance even in a recombination proficient strain. Our results indicate that an SOS-induced host system can maintain an R1162 derivative lacking one of its initiation sites.