Gene encoding sigma E is transcribed from a sigma A-like promoter in Bacillus subtilis.
Gene encoding sigma E is transcribed from a sigma A-like promoter in Bacillus subtilis.
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编码 sigma E 的基因由枯草芽孢杆菌中的 sigma A 样启动子转录。
DOI：
10.1128/jb.170.7.3058-3064.1988
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发表时间：
1988
影响因子：
3.2
通讯作者：
MoranJr,CP
中科院分区：
文献类型：
--
作者：
Kenney,TJ;Kirchman,PA;MoranJr,CP
枯草芽孢杆菌产生几种RNA聚合酶因子。这些因子中至少有两个对于内孢子的形成是必不可少的，即存在于营养细胞中的sigma H和在内孢子形成开始后才产生的sigma E。编码sigmae的结构基因是spoIIG操纵子的一部分，它在孢子形成后转录。我们已经确定了转录起始点和spoIIG启动子的核苷酸序列。该启动子包含的序列与E sigma A（营养细胞中RNA聚合酶的主要形式）使用的启动子-10和-35区域的序列相似。该启动子的不同寻常之处在于，这些假定的sigma A接触位点相距22个碱基对，而不是典型的17或18个碱基对。-10-like序列的单碱基替换降低了spoIIG启动子在体内的利用率。此外，在体外实验中，E sigma A，而不是E sigma H和其他次级形式的RNA聚合酶，准确地启动了spoIIG启动子的转录；因此，我们认为E sigma A在体内转录破坏操纵子。在营养细胞中，-35-like序列的碱基替换导致启动子的组成性转录；因此，这种孢子特异性转录的调控可能涉及一种新的机制。
Bacillus subtilis produces several RNA polymerase sigma factors. At least two of these factors are essential for endospore formation, sigma H, which is present in vegetative cells, and sigma E, which is produced exclusively after the start of endospore formation. The structural gene that encodes sigma E is part of the spoIIG operon, which is transcribed after the onset of sporulation. We have determined the starting point of transcription and the nucleotide sequence of the spoIIG promoter. This promoter contains sequences that are similar to those found at the -10 and -35 regions of promoters that are used by E sigma A, the primary form of RNA polymerase in vegetative cells. The unusual feature of this promoter is that these putative sigma A contact sites are separated by 22 base pairs, rather than the typical 17 or 18 base pairs. Single-base substitutions in the -10-like sequence reduced utilization of the spoIIG promoter in vivo. Furthermore, E sigma A, but not E sigma H and other secondary forms of RNA polymerase, accurately initiated transcription from the spoIIG promoter in an in vitro assay; therefore, we suggest that E sigma A transcribes the spoIIG operon in vivo. A base substitution in the -35-like sequence caused constitutive transcription from the promoter in vegetative cells; therefore, regulation of this sporulation-specific transcription may involve a novel mechanism.