Termination of DNA replication in Escherichia coli requires a trans-acting factor.
Termination of DNA replication in Escherichia coli requires a trans-acting factor.
复制标题
大肠杆菌中 DNA 复制的终止需要反式作用因子。
DOI：
10.1128/jb.170.2.662-668.1988
复制
发表时间：
1988
影响因子：
3.2
通讯作者：
Kuempel,PL
中科院分区：
文献类型：
--
作者：
Hill,TM;Kopp,BJ;Kuempel,PL
大肠杆菌染色体的末端区域包含两个抑制 DNA 复制叉进展的位点。这些终止位点指定为 T1 和 T2，在遗传图谱上相距 7.5 分钟（350 kb），位于终止区域的末端。它们表现出极性（它们阻止复制叉朝一个方向移动，但不阻止另一个方向）并抑制已经通过并即将离开终点的复制叉。我们利用末端区域的缺失突变来更准确地定位T1和T2的位置，并启动复制叉抑制机制的研究。我们将 T1 和 T2 的边界分别缩小到 20 和 4 kb。 T1 映射在末端区域物理图上的 kb 80 和 100 之间（J. P. Bouché, J. Mol. Biol. 154:1-20, 1982），T2 映射在 kb 438 和 442 之间。此外，我们在此报告包含 T2 终止位点的区域的删除使 T1 失活。在质粒上提供 T2 区域可恢复 T1 功能，证明 T1 复制的抑制需要映射在终止位点 T2 附近的反式作用因子。我们将这种新确定的末端功能称为末端利用物质（tus）。
The terminus region of the Escherichia coli chromosome contains two sites that inhibit the progression of DNA replication forks. These termination sites, designated T1 and T2, are separated by 7.5 min (350 kilobases [kb]) on the genetic map and are located at the extremities of the terminus region. They demonstrate polarity (they stop replication forks traveling in one direction but not the other) and inhibit replication forks that have passed through and are about to leave the terminus. We have used deletion mutations in the terminus region to map the locations of T1 and T2 more accurately and to initiate studies on the mechanism of replication fork inhibition. We have narrowed the boundaries of T1 and T2 to 20 and 4 kb, respectively. T1 maps between kb 80 and 100 on the physical map of the terminus region (J. P. Bouché, J. Mol. Biol. 154:1-20, 1982), and T2 maps between kb 438 and 442. In addition, we report here that deletion of the region containing the T2 termination site inactivated T1. Supplying the T2 region on a plasmid restored T1 function, demonstrating that inhibition of replication at T1 requires a trans-acting factor which maps in the vicinity of termination site T2. We have called this newly identified terminus function the termination utilization substance (tus).