Regulation of the production of Bacillus subtilis extracellular proteases

枯草芽孢杆菌外切酶的产生受到一个双组分调控系统degs-deGU的调控。此外，所谓的辅助因子如deGR也在这一过程中发挥作用。这些因素在DEGS/U之前起作用，似乎在感知环境条件方面发挥作用。这项研究是通过DECR调节来阐明允许枯草芽孢杆菌细胞产生外切酶的信号流。取得了以下研究结果：1.增强DegR.i正调控功能的prob基因的特性在筛选一个在多拷贝DegR存在下增强外源蛋白水解酶产生的基因的过程中，我们获得了prob基因，并将其定位在枯草杆菌物理图谱上的1,373kb处。Ii)ProB的增强效果需要DEGS，这表明ProB功能是通过DEGS/DECU信令系统实现的。3)多拷贝探针对DECR的表达有抑制作用。…的调控机制更多的F度表达。I)通过引物延伸分析确定转录起始点。在多拷贝proB存在的情况下，DegR的转录被抑制。ii)当Sigma^D的结构基因sigD被破坏时，DegR的表达被上调。(3)ProB的抑制作用依赖于DegS。4)ProB抑制HAG的表达也依赖于Sigma、D因子。V)当DegR启动子的-10序列从Sigma^D型改变为Sigma^A型时，ProB不再抑制DegR的表达。(Vi)ProB不影响sigD的表达。因此，我们认为ProB抑制sigma^D的功能，但不抑制sigma^D的合成，从而抑制sigma^D依赖的DegR的表达。ProB是一种在脯氨酸生物合成中起作用的酶，因此，它调节DegR表达的事实表明，细胞的营养条件参与了DegR表达，导致外源蛋白水解酶的产生。较少

The production of Bacillus subtilis exoprotease are subject to regulation by a two-component regulatory system, DegS-DegU.In addition so-called accessory factors such as degR also function in this process. These factors work before DegS/U and seem to play a role in sensing environmental conditions. This study was undertaken to clarify through degR regulation the flow of signals that allow Bacillus subtilis cells to produce exoproteases. Following results were obtained.1. Characterization of the proB gene that enhances the positive regulatory function of DegR.i) During the course of screening for a gene that enhances the production of the exoproteases in the presence of multicopy degR,we obtained the proB gene and mapped it at 1,373 kb on the physical map of B,subtilis. ii) ProB required DegS for its enhanceing effect, indicating that the ProB function is through the DegS/DegU signalling system. iii) Multicopy proB showed an inhibitory effect on degR expression.2. Regulatory mechanism o … More f degR expression. i) We determined the transcription start point by a primer extension analysis. Transcription of degR was found to be inhibited in the presence of multicopy proB.ii) When sigD,the structural gene for sigma^D, was disrupted, the expression of degR was aboished. iii) The inhibitory effect of ProB was dependent on DegS.iv) ProB inhibited the expression of hag that is also dependent on the sigma^D factor. v) Inhibition of degR expression by ProB was no more seen when the -10 sequence of the degR promoter was changed from a sigma^D type to a sigma^A type promoter. vi) ProB,however, did not affect the expression of sigD.From these results, we conclude that ProB inhibits the function of sigma^D but not the synthesis of it, resulting in inhibition of sigma^D-dependent degR expression. ProB is an enzyme that functions in the proline biosynthesis, and therfore, the fact that it regulates degR expression suggests an involvement of a cell's nutritional condition in degR expression, leading to the production of the exoproteases. Less