Functional regions of the N-terminal domain of the antiterminator RfaH.
Functional regions of the N-terminal domain of the antiterminator RfaH.
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DOI：
10.1111/j.1365-2958.2010.07056.x
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发表时间：
2010-04
影响因子：
3.6
通讯作者：
Artsimovitch I
中科院分区：
文献类型：
--
作者：
Belogurov GA;Sevostyanova A;Svetlov V;Artsimovitch I
RfaH是一种细菌延伸因子，其增加几个长的、水平获得的操纵子中的远端基因的表达。RfaH在RNA链延伸期间通过与称为ops的DNA元件的特异性相互作用被募集到转录复合物中。募集后，RfaH保持与RNA聚合酶（RNAP）结合，并通过减少RNAP在某些因子非依赖性和Rho依赖性信号下的暂停和终止而充当抗终止剂。RfaH由通过柔性接头连接的两个结构域组成。N-末端RfaH结构域（RfaHN）识别ops元件，与RNAP结合并减少体外暂停和终止。在此报告的结构域中的单取代的功能分析表明，三个独立的RfaHN区域介导这些功能。我们认为RfaHN一侧的极性斑块在募集过程中与非模板DNA链相互作用，而RfaHN另一侧的疏水表面在整个操纵子的转录过程中保持与β′亚基夹螺旋结构域结合。第三个区域显然是为RfaH结合到转录复合物，但所需的RNAP的抗终止修饰。
RfaH is a bacterial elongation factor that increases expression of distal genes in several long, horizontally acquired operons. RfaH is recruited to the transcription complex during RNA chain elongation through specific interactions with a DNA element called ops. Following recruitment, RfaH remains bound to RNA polymerase (RNAP) and acts as an antiterminator by reducing RNAP pausing and termination at some factor-independent and Rho-dependent signals. RfaH consists of two domains connected by a flexible linker. The N-terminal RfaH domain (RfaHN) recognizes the ops element, binds to the RNAP and reduces pausing and termination in vitro. Functional analysis of single substitutions in this domain reported here suggests that three separate RfaHN regions mediate these functions. We propose that a polar patch on one side of RfaHN interacts with the non-template DNA strand during recruitment, whereas a hydrophobic surface on the opposite side of RfaHN remains bound to the β′ subunit clamp helices domain throughout transcription of the entire operon. The third region is apparently dispensable for RfaH binding to the transcription complex but is required for the antitermination modification of RNAP.
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影响因子：
64.5
作者：
Artsimovitch, I;Landick, R
通讯作者：
Landick, R
影响因子：
56.9
作者：
Cardinale, Christopher J.;Washburn, Robert S.;Nudler, Evgeny
通讯作者：
Nudler, Evgeny
影响因子：
16
作者：
Kettenberger, H;Armache, KJ;Cramer, P
通讯作者：
Cramer, P
影响因子：
2.1
作者：
STEVENS, MP;HANFLING, P;ROBERTS, IS
通讯作者：
ROBERTS, IS
影响因子：
3.2
作者：
GUZMAN, LM;BELIN, D;BECKWITH, J
通讯作者：
BECKWITH, J