Control site location and transcriptional regulation in Escherichia coli
Control site location and transcriptional regulation in Escherichia coli
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DOI：
10.1128/mr.55.3.371-394.1991
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发表时间：
1991-09
期刊：
影响因子：
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通讯作者：
J. Collado-Vides;B. Magasanik;J. D. Gralla
中科院分区：
文献类型：
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作者：
J. Collado-Vides;B. Magasanik;J. D. Gralla
对119个大肠杆菌启动子的调控区进行了分析，并对调控位点的位置进行了编目。出现了以下意见。(i)超过95%的启动子与至少一种其他启动子共调控。(ii)实际上，所有σ 70启动子在近端位置含有至少一个调节位点，相对于转录起始点至少接触位置-65。在缺少近端位点的情况下，还没有明确的上游调控的例子。(iii)调节子内的算子出现在非常可变的近端位置。相比之下，调节子的近端激活位点更加固定。(iv)相对于转录起始点，在大约-20位下游存在激活元件的禁区。相比之下，操作符可以出现在整个近端区域。当激活元素出现在禁区时，它们会抑制。这些例子通常涉及自动调节。(v)大约40%的阻遏型启动子含有操纵子重复。这些发生在某些调节子中，其中复制似乎是阻遏物作用的必要条件，或者发生在受复杂调控的启动子中。(vi)远程操纵子重复发生在大约10%的可阻遏启动子中。它们通常出现在多启动子区域被环AMP受体蛋白共同调节时。(vii)σ 54启动子不需要近端或精确定位的激活元件，并且通常不受负调控。对上述所有观察结果进行了分析。
The regulatory regions for 119 Escherichia coli promoters have been analyzed, and the locations of the regulatory sites have been cataloged. The following observations emerge. (i) More than 95% of promoters are coregulated with at least one other promoter. (ii) Virtually all sigma 70 promoters contain at least one regulatory site in a proximal position, touching at least position -65 with respect to the start point of transcription. There are not yet clear examples of upstream regulation in the absence of a proximal site. (iii) Operators within regulons appear in very variable proximal positions. By contrast, the proximal activation sites of regulons are much more fixed. (iv) There is a forbidden zone for activation elements downstream from approximately position -20 with respect to the start of transcription. By contrast, operators can occur throughout the proximal region. When activation elements appear in the forbidden zone, they repress. These latter examples usually involve autoregulation. (v) Approximately 40% of repressible promoters contain operator duplications. These occur either in certain regulons where duplication appears to be a requirement for repressor action or in promoters subject to complex regulation. (vi) Remote operator duplications occur in approximately 10% of repressible promoters. They generally appear when a multiple promoter region is coregulated by cyclic AMP receptor protein. (vii) Sigma 54 promoters do not require proximal or precisely positioned activator elements and are not generally subject to negative regulation. Rationales are presented for all of the above observations.