Cis-acting site on bipolar migration of the replication origin on the E.coil chromosome

大肠杆菌染色体上复制起点双极迁移的顺式作用位点

• 批准号: 14380331
• 负责人: NIKI Hironori
• 金额: $ 9.22万
• 依托单位: National Institute of Genetics
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14380331/
• 关键词: bacteria; migration; nucleoids; partitioning; segregation; 分配機構; セントロメア

During replication of the Escherichia coil chromosome, the replicated Ori domains migrate towards opposite cell poles, suggesting that a cis-acting site for bipolar migration is located in this region. To identify this cis-acting site, a series of mutants was constructed by splitting subchromosomes from the original chromosome. One mutant, containing a 720 kb subchromosome, was found to be defective in the bipolar positioning of oriC. The creation of deletion mutants allowed the identification of migS, a 25 bp sequence, as the cis-acting site for the bipolar positioning of oriC. When migS was located at the replication terminus, the chromosomal segment showed bipolar positioning. migS was able to rescue bipolar migration of plasmid DNA containing, a mutation in the SopABC partitioning system. Interestingly, multiple copies of the migS sequence on a plasmid in trans inhibited the bipolar positioning of oriC. Taken together, these findings indicate that migS plays a crucial role in the bipolar positioning of oriC. In addition, real-time analysis of the dynamic morphological changes of nucleoids in wild-type and migS mutants suggests that bipolar positioning of the replicated oriC contributes to nucleoid organization.

在大肠杆菌染色体复制过程中，复制的 Ori 结构域向相反的细胞极迁移，表明双极迁移的顺式作用位点位于该区域。为了识别这个顺式作用位点，通过从原始染色体分裂亚染色体来构建一系列突变体。一种含有 720 kb 亚染色体的突变体被发现在 oriC 的双极定位中存在缺陷。缺失突变体的创建允许鉴定 migS（25 bp 序列）作为 oriC 双极定位的顺式作用位点。当migS位于复制末端时，染色体片段呈现双极定位。 migS 能够挽救含有 SopABC 分配系统突变的质粒 DNA 的双极迁移。有趣的是，质粒上反式migS序列的多个拷贝抑制了oriC的双极定位。总而言之，这些发现表明 migS 在 oriC 的双极定位中发挥着至关重要的作用。此外，对野生型和 migS 突变体中核的动态形态变化的实时分析表明，复制的 oriC 的双极定位有助于核的组织。

项目成果

Yamaichi, Y., Niki, H.: "migS, a cis-acting site that affects bipolar positioning of oriC on the Escherichia coli chromosome"EMBO J. 23. 221-233 (2004)

Yamaichi, Y., Niki, H.：“migS，影响大肠杆菌染色体上 oriC 双极定位的顺式作用位点”EMBO J. 23. 221-233 (2004)

Yoshiharu Yamaichi, Hironori Niki: "migS, a cis acting site that affects bipolar migration of oriC on the Escherichia coli chromosome"The EMBO Journal. 23. 221-233 (2004)

Yoshiharu Yamaichi、Hironori Niki：“migS，一个影响大肠杆菌染色体上 oriC 双极迁移的顺式作用位点”EMBO 杂志。

Yamaichi, Y., Niki, Y.: "migS, a cis acting site that affects bipolar migratio of oriC on the Escherichia coli chromosome"The EMBO Journal.. 23. 221-233 (2004)

Yamaichi, Y., Niki, Y.：“migS，影响大肠杆菌染色体上 oriC 双极迁移的顺式作用位点”The EMBO Journal.. 23. 221-233 (2004)