RNA polymerase mutants that destabilize RNA polymerase-promoter complexes alter NTP-sensing by rrn P1 promoters
RNA polymerase mutants that destabilize RNA polymerase-promoter complexes alter NTP-sensing by rrn P1 promoters
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DOI：
10.1006/jmbi.1998.1779
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发表时间：
1998-06-05
影响因子：
5.6
通讯作者：
Gourse, RL
中科院分区：
文献类型：
--
作者：
Bartlett, MS;Gaal, T;Gourse, RL
大肠杆菌rpoB或rpoC的突变被发现影响rrn P1启动子的转录，rpoB或rpoC被选为赋予relA斑点菌株原生性的能力。两株突变株(βRH454和β‘Delta 215-220)降低了rrn P1核心启动子-LacZ融合的转录，但降低了对照启动子-LacZ融合的转录。纯化的突变体RNAP与RRn P1启动子形成的复合体比野生型RNAP的启动子更不稳定，需要高浓度的启动NTP才能有效转录RRn P1。Rrn P1核心启动子与突变的RNAP的复合体的不稳定性及其调节特性的改变支持了最近提出的通过改变启动NTP的浓度来控制rRNA转录的模型。我们进一步认为，突变的RNAP使启动子复合体不稳定，模拟了ppGpp的影响，根据特定启动子的动力学性质减少或增加转录。(C)1998年学术出版社有限公司。
Mutations in Escherichia coli rpoB or rpoC, selected for the ability to confer prototrophy on relA spoT strains, were found to affect transcription from rrn P1 promoters. Two mutant strains (beta RH454 and beta' Delta 215-220) reduced transcription of rrn P1 core promoter-lacZ fusions but hot of control promoter-lacZ fusions. Purified mutant RNAPs formed complexes with rrn P1 promoters that were much less stable than those formed by wild-type RNAP and required high concentrations of the initiating NTP for efficient rrn P1 transcription. The instability of the rrn P1 core promoter complexes with the mutant RNAPs and their altered regulatory properties support a recently proposed model for the control of rRNA transcription by changing concentrations of the initiating NTPs. We further suggest that destabilization of promoter complexes by the mutant RNAPs mimics effects of ppGpp, decreasing or increasing transcription depending on the kinetic properties of the specific promoter. (C) 1998 Academic Press Limited.