The dksA promoter is negatively feedback regulated by DksA and ppGpp.
The dksA promoter is negatively feedback regulated by DksA and ppGpp.
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dksA 启动子受 DksA 和 ppGpp 负反馈调节。
DOI：
10.1111/j.1365-2958.2011.07649.x
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发表时间：
2011-06
影响因子：
3.6
通讯作者：
Gourse RL
中科院分区：
文献类型：
--
作者：
Chandrangsu P;Lemke JJ;Gourse RL
大肠杆菌DksA是一种RNA聚合酶(RNAP)结合蛋白，调节许多启动子，包括rRNA、许多核糖体蛋白、鞭毛的组成部分和几种氨基酸的生物合成。以前的工作表明，Dks A蛋白水平在不同的生长条件下变化不大。我们在这里证明了DksA是一种稳定的蛋白质，其水平通过一个负反馈环保持恒定，在这个负反馈环中，来自DksA启动子的转录被DksA蛋白及其辅因子ppGpp共同抑制。我们通过引物延伸定位了主要的dks A启动子，表明它的活性在缺乏Dks A的菌株中增加，Dks A蛋白在外源启动子表达时积累，Dks A在体外直接抑制转录，因为它与纯化的成分一起发生，并且这种抑制与Dks A对dks A启动子复合体寿命的影响有关。这项工作为在大肠杆菌中维持细胞内恒定的Dks A水平提供了机制基础，并支持ppGpp/Dks A的转录调控来自小分子辅因子浓度的波动而不是Dks A本身的模型。
Escherichia coli DksA is an RNA polymerase (RNAP)-binding protein required for the regulation of a number of promoters, including those for the biosynthesis of rRNA, many ribosomal proteins, components of the flagellum, and several amino acids. Previous work demonstrated that DksA protein levels do not vary greatly in different growth conditions. We show here that DksA is a stable protein whose levels are kept constant by a negative feedback loop in which transcription from the dksA promoter is inhibited by DksA protein in conjunction with its cofactor ppGpp. We map the primary dksA promoter by primer extension, show that its activity increases in a strain lacking DksA, that the DksA protein accumulates when expressed from an exogenous promoter, that inhibition of transcription by DksA is direct since it occurs with purified components in vitro, and that inhibition correlates with effects of DksA on the lifetime of the dksA promoter complex. This work provides a mechanistic basis for the maintenance of constant cellular levels of DksA in E. coli and supports the model that transcription regulation by ppGpp/DksA derives from fluctuations in the concentrations of the small molecule cofactor rather than of DksA itself.
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影响因子：
16
作者：
Flynn, JM;Neher, SB;Baker, TA
通讯作者：
Baker, TA
影响因子：
3.6
作者：
Perron, K;Comte, R;van Delden, C
通讯作者：
van Delden, C
DOI：
10.1073/pnas.0501170102
发表时间：
2005-05-31
影响因子：
11.1
作者：
Paul, BJ;Berkmen, MB;Gourse, RL
通讯作者：
Gourse, RL
DOI：
10.1038/nbt0184-81
发表时间：
1984-01-01
期刊：
BIO-TECHNOLOGY
影响因子：
--
作者：
MASUI, Y;MIZUNO, T;NOUYE, M
通讯作者：
NOUYE, M
影响因子：
3.6
作者：
Lemke JJ;Durfee T;Gourse RL
通讯作者：
Gourse RL