...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>PLoS Genetics >The nucleoid occlusion factor Noc controls DNA replication initiation in Staphylococcus aureus
【24h】

The nucleoid occlusion factor Noc controls DNA replication initiation in Staphylococcus aureus

机译：核闭塞因子NOC控制金黄色葡萄球菌中的DNA复制引发

获取原文
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Successive division events in the spherically shaped bacterium Staphylococcus aureus are oriented in three alternating perpendicular planes. The mechanisms that underlie this relatively unique pattern of division and coordinate it with chromosome segregation remain largely unknown. Thus far, the only known spatial regulator of division in this organism is the nucleoid occlusion protein Noc that inhibits assembly of the cytokinetic ring over the chromosome. However, Noc is not essential in S. aureus, indicating that additional regulators are likely to exist. To search for these factors, we screened for mutants that are synthetic lethal with Noc inactivation. Our characterization of these mutants led to the discovery that S. aureus Noc also controls the initiation of DNA replication. We show that cells lacking Noc over-initiate and mutations in the initiator gene dnaA suppress this defect. Importantly, these dnaA mutations also partially suppress the division problems associated with Δnoc. Reciprocally, we show that over-expression of DnaA enhances the over-initiation and cell division phenotypes of the Δnoc mutant. Thus, a single factor both blocks cell division over chromosomes and helps to ensure that new rounds of DNA replication are not initiated prematurely. This degree of economy in coordinating key cell biological processes has not been observed in rod-shaped bacteria and may reflect the challenges posed by the reduced cell volume and complicated division pattern of this spherical pathogen.
机译：球形葡萄球菌中的连续分割事件在三个交替的垂直平面中取向。利用染色体隔离的这种相对独特的分裂模式和坐标的机制仍然很大程度上是未知的。到目前为止，该生物体中唯一已知的划分的空间调节剂是抑制在染色体上的细胞内肾上腺素组装的核闭塞蛋白NOC。然而，NOC在金黄色葡萄球菌中不是必需的，表明额外的调节剂可能存在。为了搜索这些因素，我们筛选突变体，该突变体是具有NOC灭活的合成致死。我们对这些突变体的表征导致了发现金黄色葡萄球菌NOC的发现也控制了DNA复制的开始。我们表明，缺乏缺乏引发剂基因DNAA中的NOC的细胞抑制了这种缺陷。重要的是，这些DNAA突变也部分抑制与Δnoc相关的分裂问题。相互作用，我们表明DNAA的过表达增强了Δnoc突变体的过度启动和细胞分裂表型。因此，两个因子均阻断细胞分裂在染色体上，有助于确保新的DNA复制未过早启动。在杆状细菌中未观察到协调关键细胞生物过程中的这种经济性，并且可以反映这种球形病原体的细胞体积和复杂分裂模式所带来的挑战。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号