Transcription regulation of restriction-modification system Esp1396I.
Transcription regulation of restriction-modification system Esp1396I.
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DOI：
10.1093/nar/gkp210
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发表时间：
2009-06
影响因子：
14.9
通讯作者：
Severinov K
中科院分区：
文献类型：
--
作者：
Bogdanova E;Zakharova M;Streeter S;Taylor JEN;Heyduk T;Kneale G;Severinov K
限制性修饰系统Esp 1396 I的会聚转录的限制性（R）和甲基化酶（M）基因受到形成CR操纵子的一部分的控制器（C）蛋白的严格调控。我们绘制了每个启动子的转录起始位点，并研究了C.Esp1396I在体内和体外的调控作用。通过DNA足迹法和一系列生物物理技术分析了CR和M启动子处的C蛋白结合。CR启动子的远端和近端C蛋白结合位点分别负责激活和抑制。相比之下，C蛋白二聚体结合到M启动子的单个位点以抑制基因，其亲和力比CR启动子大得多。因此，在初始宿主中建立系统期间，M启动子的活性被提前关闭，从而防止甲基化酶的过度合成。启动子结合位点的突变分析表明，四核苷酸反向重复序列长期以来被认为是重要的C-蛋白结合到DNA是不太重要的比以前认为的。相反，这些重复序列之外的与C.Esp139I相关的元素似乎对相互作用至关重要，并根据与CR启动子结合的C.Esp139I最近的晶体结构进行了讨论。
The convergently transcribed restriction (R) and methylase (M) genes of the Restriction–Modification system Esp1396I are tightly regulated by a controller (C) protein that forms part of the CR operon. We have mapped the transcriptional start sites from each promoter and examined the regulatory role of C.Esp1396I in vivo and in vitro. C-protein binding at the CR and M promoters was analyzed by DNA footprinting and a range of biophysical techniques. The distal and proximal C-protein binding sites at the CR promoter are responsible for activation and repression, respectively. In contrast, a C-protein dimer binds to a single site at the M-promoter to repress the gene, with an affinity much greater than for the CR promoter. Thus, during establishment of the system in a naïve host, the activity of the M promoter is turned off early, preventing excessive synthesis of methylase. Mutational analysis of promoter binding sites reveals that the tetranucleotide inverted repeats long believed to be important for C-protein binding to DNA are less significant than previously thought. Instead, symmetry-related elements outside of these repeats appear to be critical for the interaction and are discussed in terms of the recent crystal structure of C.Esp139I bound to the CR promoter.
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影响因子：
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作者：
Schuck, P
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Schuck, P
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作者：
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作者：
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