Undesigned Selection for Replication Termination of Bacterial Chromosomes
Undesigned Selection for Replication Termination of Bacterial Chromosomes
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DOI：
10.1016/j.jmb.2014.06.005
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发表时间：
2014-08-12
影响因子：
5.6
通讯作者：
Itaya, Mitsuhiro
中科院分区：
文献类型：
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作者：
Kono, Nobuaki;Arakawa, Kazuharu;Itaya, Mitsuhiro
细菌染色体中的oriC DNA复制起点，其位置似乎是物理识别的，是由相关分子机制遗传调节的。相比之下，对于许多细菌复制子，末端的位置仍然模糊，除了terC，在某些细菌中提出和充分研究的染色体终止位点。terC基因座由其结合蛋白的特异性序列组成，位于oriC的相反位点，围绕oriC-terC轴呈现对称结构。在这里，我们研究了枯草芽孢杆菌168菌株的轴受阻，发现天然terC功能是强大的。然而，消除末端区域特异性结合蛋白导致天然terC位点不用于终止;相反，在与oriC完全相反的位置选择新的末端。我们的结论是，复制一般终止于两个接近的复制体相遇的位点。该位点被自动选择，并且以相同速率移动的两个复制体支持相对于oriC对称的染色体结构。该规则甚至被人工染色体验证，而不考虑oriC，对于由两个复制体管理的复制子应该是通用的。(C)2014作者爱思唯尔有限公司出版
The oriC DNA replication origin in bacterial chromosomes, the location of which appears to be physically identified, is genetically regulated by relevant molecular machinery. In contrast, the location of the terminus remains obscure for many bacterial replicons, except for terC, the proposed and well-studied chromosome termination site in certain bacteria. The terC locus, which is composed of specific sequences for its binding protein, is located at a site opposite from oriC, exhibiting a symmetric structure around the oriC-terC axis. Here, we investigated Bacillus subtilis 168 strains whose axes were hindered and found that the native terC function was robust. However, eradication of terminus region specific binding protein resulted in the natural terC sites not being used for termination; instead, new termini were selected at a location exactly opposite to oriC. We concluded that replication generally terminates at the loci where the two approaching replisomes meet. This site was automatically selected, and two replisomes moving at the same rate supported symmetrical chromosome structures relative to oriC. The rule, which was even validated by artificial chromosomes irrespective of oriC, should be general for replicons administered by two replisomes. (C) 2014 The Authors. Published by Elsevier Ltd.