Spo0A binds to a promoter used by sigma A RNA polymerase during sporulation in Bacillus subtilis.
Spo0A binds to a promoter used by sigma A RNA polymerase during sporulation in Bacillus subtilis.
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在枯草芽孢杆菌孢子形成过程中，Spo0A 与 sigma A RNA 聚合酶使用的启动子结合。
DOI：
10.1073/pnas.88.10.4533
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发表时间：
1991
影响因子：
11.1
通讯作者：
MoranJr,CP
中科院分区：
文献类型：
--
作者：
Satola,S;Kirchman,PA;MoranJr,CP
对 spoIIG 启动子中 56 个单碱基对取代的影响的检查以及 spo0A 产物 (Spo0A) 与该启动子体外相互作用的研究表明，Spo0A 直接发挥作用，使该启动子能够被 sigma A 相关 RNA 聚合酶 (EC 2.7.7.6) 使用。来自枯草芽孢杆菌的 spoIIG 操纵子在孢子形成过程中由含有 σ A 的 RNA 聚合酶转录，σ A 是营养细胞中的主要 σ 因子。 spoIIG 启动子的不同寻常之处在于它包含与 sigma A 相关 RNA 聚合酶使用的启动子 -10 和 -35 区域中发现的序列相似的序列，但这些 sigma A 样识别序列由 22 个碱基对分隔，而不是典型的 17 或 18 个碱基对。我们发现-35样序列周围的单碱基对替换以及该位置上游区域（位置-87附近）的替换降低了启动子活性。使用 DNase I 保护和电泳凝胶迁移率变动测定来证明 Spo0A 在体外与这些区域特异性结合。显然，-35 样序列是 Spo0A 结合位点的一部分，因此可能不是 sigma A 识别序列。这些结果支持这样的模型：在内生孢子形成开始后，Spo0A 激活 spoIIG 启动子。
Examination of the effects of 56 single-base-pair substitutions in the spoIIG promoter and studies of the interaction of the spo0A product (Spo0A) with this promoter in vitro demonstrated that Spo0A acts directly to enable this promoter to be used by sigma A-associated RNA polymerase (EC 2.7.7.6). The spoIIG operon from Bacillus subtilis is transcribed during sporulation by a form o RNA polymerase containing sigma A, the primary sigma factor in vegetative cells. The spoIIG promoter is unusual in that it contains sequences that are similar to those found at the -10 and -35 regions of promoters that are used by sigma A-associated RNA polymerase, but these sigma A-like recognition sequences are separated by 22 base pairs rather than the typical 17 or 18 base pairs. We found that single-base-pair substitutions in the around the -35-like sequence, and substitutions in a region upstream from this position, around position -87, reduced promoter activity. DNase I protection and electrophoretic gel mobility shift assays were used to demonstrate that Spo0A binds specifically to these regions in vitro. Evidently, the -35-like sequence is part of a Spo0A binding site and therefore is possibly not a sigma A-recognition sequence. These results support a model in which Spo0A activates the spoIIG promoter after the onset of endospore formation.