...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>PLoS Genetics >A Toxin–Antitoxin System Promotes the Maintenance of an Integrative Conjugative Element
【24h】

A Toxin–Antitoxin System Promotes the Maintenance of an Integrative Conjugative Element

机译：毒素-抗毒素系统促进整合结合因子的维持

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

摘要

SXT is an integrative and conjugative element (ICE) that confers resistance to multiple antibiotics upon many clinical isolates of Vibrio cholerae. In most cells, this ～100 Kb element is integrated into the host genome in a site-specific fashion; however, SXT can excise to form an extrachromosomal circle that is thought to be the substrate for conjugative transfer. Daughter cells lacking SXT can theoretically arise if cell division occurs prior to the element's reintegration. Even though ～2% of SXT-bearing cells contain the excised form of the ICE, cells that have lost the element have not been detected. Here, using a positive selection-based system, SXT loss was detected rarely at a frequency of ～1×10?7. As expected, excision appears necessary for loss, and factors influencing the frequency of excision altered the frequency of SXT loss. We screened the entire 100 kb SXT genome and identified two genes within SXT, now designated mosA and mosT (for maintenance of SXT Antitoxin and Toxin), that promote SXT stability. These two genes, which lack similarity to any previously characterized genes, encode a novel toxin-antitoxin pair; expression of mosT greatly impaired cell growth and mosA expression ameliorated MosT toxicity. Factors that promote SXT excision upregulate mosAT expression. Thus, when the element is extrachromosomal and vulnerable to loss, SXT activates a TA module to minimize the formation of SXT-free cells.
机译：SXT是一种整合共轭元件（ICE），可在许多临床分离的霍乱弧菌中赋予对多种抗生素的抗性。在大多数细胞中，约100 Kb的元素以位点特异性方式整合到宿主基因组中。但是，SXT可以切除形成染色体外的环，该环被认为是共轭转移的底物。如果细胞分裂发生在元件重新整合之前，理论上就会出现缺乏SXT的子细胞。即使约2％的SXT携带细胞含有ICE的切除形式，但仍未检测到丢失元素的细胞。在这里，使用基于正选择的系统，很少以〜1×10？7的频率检测到SXT损失。不出所料，切除似乎是造成损失的必要条件，影响切除频率的因素改变了SXT损失的频率。我们筛选了整个100 kb SXT基因组，并确定了SXT中的两个基因，这些基因现在称为mosA和mosT（用于维持SXT抗毒素和毒素），可促进SXT稳定性。这两个基因与以前鉴定过的基因缺乏相似性，编码一个新的毒素-抗毒素对。 mosT的表达大大削弱了细胞的生长，而mosA的表达改善了MosT的毒性。促进SXT切除的因子上调mosAT表达。因此，当元件是染色体外的并且容易丢失时，SXT激活TA模块以最小化无SXT细胞的形成。

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