膜相关的s因子破坏了埃舍里希亚大肠杆菌中rRNA操作子的聚类
1Department of Molecular Biosciences and LaMontagne Center for Infectious Diseases, The University of Texas at Austin, Austin, Texas, United States of America.
PLoS biology
|April 17, 2025
概括
热冲击破坏了Escherichia coli中的核糖体RNA (rrn) 操作子集群. 高水平的西格玛H (σH) 和FecI西格玛因子也会破坏聚类,这表明这些西格玛因子在基因组组织中的作用.
科学领域:
- 微生物学 微生物学
- 分子生物学分子生物学
- 基因组学就是基因组学.
背景情况:
- 大肠杆菌的核糖体RNA (rrn) 操作子表现出空间聚类,尽管基因组间的长距离相互作用稀少.
- 目前对 rrn 操作子集群机制的理解仅限于 cis 作用元素.
研究的目的:
- 确定涉及Escherichia coli体内的核糖体RNA (rrn) 操作子的空间组织和集群的转作用因子.
- 调查西格玛因子在调节运算群集中的作用.
主要方法:
- 通过化学和物理手段扰乱大肠杆菌,包括热冲击.
- 对升高的西格玛因子表达 (σH,FecI,σD) 对 rrn操作子聚类的影响进行分析.
- 通过核心-RNA聚合酶 (RNAP) 相互作用和DNA结合试验评估西格玛因子活性.
主要成果:
- 发现热冲击会破坏核糖体RNA (rrn) 操作子的聚类.
- 仅仅西格玛H (σH) 的高表达就足以扰乱rrn操作子集群,独立于热应力.
- σH的抗聚类活性需要核心-RNAP相互作用和DNA结合,但不需要转录活性.
- 高度表达FecI,ECF的西格玛因子,也扰乱集群,其活动被 σD 抑制.
- σD表达抑制了 σH 和 FecI 的抗聚类活性,这表明对核心-RNAP 的竞争.
结论:
- 西格玛因子,特别是 σH 和 FecI,在大肠杆菌中遥远的核糖体RNA (rrn) 操作子的空间组织和聚类中发挥着重要作用.
- 不同的西格玛因子之间的核心RNA聚合酶 (RNAP) 竞争可能会调节rrn操作子集群.
- 膜相关的西格玛因子可能参与协调遥远的基因组位置的聚类.
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