Termination Structures in the Escherichia coli Chromosome Replication Fork Trap
Termination Structures in the Escherichia coli Chromosome Replication Fork Trap
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DOI：
10.1016/j.jmb.2009.02.027
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发表时间：
2009-04-03
影响因子：
5.6
通讯作者：
Bell, Stephen D.
中科院分区：
文献类型：
--
作者：
Duggin, Iain G.;Bell, Stephen D.
大肠杆菌染色体含有两组相反的单向DNA复制暂停（Ter）位点，根据复制叉陷阱理论，通过将复制叉融合限制在末端区域来控制染色体复制的终止。相反，最近的一个假说认为终止发生在dif位点。使用二维琼脂糖凝胶电泳，我们研究DNA复制中间体在Ter网站和在野生型细胞中的差异。两个明确的签名，位点特异性终止-特异性复制叉逮捕和收敛复制叉-明确检测在Ter网站，但不是在dif。我们还发现了一个显着的停顿在后期阶段的复制叉收敛在Ter网站。在其天然染色体背景和质粒背景中的Ter位点处的叉暂停的定量进一步支持叉陷阱模型。(c)2009爱思唯尔有限公司保留所有权利。
The Escherichia coli chromosome contains two opposed sets of unidirectional DNA replication pause (Ter) sites that, according to the replication fork trap theory, control the termination of chromosome replication by restricting replication fork fusion to the terminus region. In contrast, a recent hypothesis suggested that termination occurs at the dif locus instead. Using two-dimensional agarose gel electrophoresis, we examine DNA replication intermediates at the Ter sites and at dif in wild-type cells. Two definitive signatures of site-specific termination-specific replication fork arrest and converging replication forks-were clearly detected at Ter sites, but not at dif. We also detected a significant pause during the latter stages of replication fork convergence at Ter sites. Quantification of fork pausing at the Ter sites in both their native chromosomal context and the plasmid context further supported the fork trap model. (c) 2009 Elsevier Ltd. All rights reserved.