Osmo-regulation of bacterial transcription via poised RNA polymerase
Osmo-regulation of bacterial transcription via poised RNA polymerase
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DOI：
10.1016/s1097-2765(04)00202-3
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发表时间：
2004-04-23
期刊：
影响因子：
16
通讯作者：
Gralla, JD
中科院分区：
文献类型：
--
作者：
Lee, SJ;Gralla, JD
适应高盐环境对于各种细胞的生存至关重要，特别是对于定植在动物肠道和泌尿道的病原菌。适应策略涉及谷氨酸钾盐的产生，其诱导产生电中性渗透剂的特定基因表达程序，同时抑制一般sigma（70）转录。这些数据表明，在大肠杆菌中，谷氨酸钾通过在sigma（38）启动子处解除抑制性聚合酶相互作用来刺激转录。这些发生在由渗透压休克启动子DNA共有序列标记的上游区域。这种破坏激活了一种稳定的RNA聚合酶进行转录。该转录程序导致产生渗透调节剂，所述渗透调节剂显示对转录仅具有微小影响，因此有助于恢复正常细胞功能。渗透压休克基因表达周期进行了讨论。
Adaptation to high-salt environments is critical for the survival of a wide range of cells, especially for pathogenic bacteria that colonize the animal gut and urinary tract. The adaptation strategy involves production of the salt potassium glutamate, which induces a specific gene expression program that produces electro-neutral osmolytes while inhibiting general sigma(70) transcription. These data show that in Escherichia coli potassium glutamate stimulates transcription by disengaging inhibitory polymerase interactions at a sigma(38) promoter. These occur in an upstream region that is marked by an osmotic shock promoter DNA consensus sequence. The disruption activates a poised RNA polymerase to transcribe. This transcription program leads to the production of osmolytes that are shown to have only minor effects on transcription and therefore help to restore normal cell function. An osmotic shock gene expression cycle is discussed.