Schmeisser F, Brannigan J A, Lewis R J, Wilkinson A J, Youngman P, Barák I
Institute of Molecular Biology, Slovak Academy of Sciences, 842 51, Bratislava, Slovak Republic.
FEMS Microbiol Lett. 2000 Apr 15;185(2):123-8. doi: 10.1111/j.1574-6968.2000.tb09049.x.
Spo0A is a two domain response regulator, a key protein in the initiation of sporulation of Bacillus subtilis. This protein controls a number of changes in gene expression that occur during the transition from stationary phase to the onset of sporulation. The phosphorylated form of Spo0A influences the transcription of a specific set of genes. In addition to others, it represses abrB and activates spoIIA and spoIIE transcription. Although the N-terminal phosphoacceptor domain is well characterised, there is limited information on the C-terminal, DNA-binding domain. Comparisons of Spo0A homologues from a number of Bacillus and Clostridium species show that the C-terminal domain contains three highly conserved regions. In this study, we have investigated the influence of spo0A mutations mapping within the C-terminal domain on transcription from the abrB, spoIIA and spoIIE promoters using lacZ fusions. Our results indicate that described mutations can be part of signalling between N- and C-terminal domains of the protein. Also, the increased expression observed from the spoIIE promoter in some Spo0A mutants might result from a stabilising function of these mutations on the transcriptional apparatus utilising sigma(A).
Spo0A是一种双结构域应答调节蛋白，是枯草芽孢杆菌芽孢形成起始过程中的关键蛋白。该蛋白控制着从稳定期到芽孢形成开始阶段发生的一系列基因表达变化。磷酸化形式的Spo0A影响一组特定基因的转录。除其他作用外，它还抑制abrB并激活spoIIA和spoIIE的转录。尽管N端磷酸受体结构域已得到充分表征，但关于C端DNA结合结构域的信息有限。对多种芽孢杆菌属和梭菌属物种的Spo0A同源物进行比较表明，C端结构域包含三个高度保守的区域。在本研究中，我们利用lacZ融合技术研究了位于C端结构域内的spo0A突变对abrB、spoIIA和spoIIE启动子转录的影响。我们的结果表明，所述突变可能是该蛋白N端和C端结构域之间信号传导的一部分。此外，在一些Spo0A突变体中观察到的spoIIE启动子表达增加可能是由于这些突变对利用sigma(A)的转录装置具有稳定作用。
