一个α螺旋到β桶域开关将转录因子RfaH转化为转化因子
Björn M Burmann1, Stefan H Knauer, Anastasia Sevostyanova
1Lehrstuhl Biopolymere und Forschungszentrum für Bio-Makromoleküle, Universität Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany.
Cell
|July 24, 2012
概括
细菌转录因子NusG和RfaH具有相似的N终端域,但它们的C终端域不同. 释放的RfaH C-终端域重新折叠成β-桶结构,增强特定操作子的翻译.
科学领域:
- 分子生物学分子生物学
- 微生物学 微生物学
- 遗传学 是一个遗传学.
背景情况:
- NusG同类物是所有生物体中转录和合过程的关键调节者.
- 大肠杆菌 (E. coli) 具有两种NusG类型,NusG和RfaH,具有不同的C端域 (CTD),但相同的N端域 (NTD).
- 这两种NTD都与延长RNA聚合酶 (RNAP) 结合,以减轻转录暂停.
研究的目的:
- 研究RfaH CTD在从NTD释放后的结构变化.
- 阐明RfaH CTD重新折叠对转录和翻译的功能影响.
- 将重新折叠的RfaH CTD与NusG CTD的结构和功能进行比较.
主要方法:
- 对RfaH和NusGCTD的结构分析.
- 生物化学测试以评估蛋白质与蛋白质之间的相互作用.
- 在体内研究以评估对基因表达的影响.
主要成果:
- 在从NTD释放后,RfaH CTD从α-螺旋转向β-桶形状重新折叠,模仿NusG CTD结构.
- 这种重新折叠使RfaH CTD与核糖体蛋白S10相互作用.
- 重复折叠的RfaH CTD增强了RfaH调节的操作数的翻译.
结论:
- RfaH CTD 的形状可塑性对其调节功能至关重要.
- RfaH充当了一种复杂的分子开关,将转录终止/反终止与翻译增强结合起来.
- 了解这些机制可以了解细菌基因调节和潜在的治疗点.
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