Interaction of AbrB, a transcriptional regulator from Bacillus subtilis with the promoters of the transition state-activated genes tycA and spoVG.
Interaction of AbrB, a transcriptional regulator from Bacillus subtilis with the promoters of the transition state-activated genes tycA and spoVG.
复制标题
AbrB（枯草芽孢杆菌的转录调节因子）与过渡态激活基因 tycA 和 spoVG 启动子的相互作用。
DOI：
10.1007/bf00261673
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发表时间：
1991
期刊：
影响因子：
--
通讯作者：
Marahiel,MA
中科院分区：
文献类型：
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作者：
Fürbass,R;Gocht,M;Zuber,P;Marahiel,MA
在枯草芽孢杆菌（bacillus subtilisistheabrbgene）中，该基因产物对从营养生长阶段到静止生长阶段激活的一些基因的转录产生负向影响。利用dna酶I和羟基自由基足迹法研究了AbrB与两个此类基因（孢子形成基因spoVG和抗生素生物合成基因tyca）启动子的相互作用。鉴定了tyca先导区和启动子区的两个结合区。inspovg结合位点位于启动子上游富含A+ t的区域。羟基自由基足迹显示，在tycav和spovgg启动子中，AbrB保护的区域是短的富含A+ t的区域，它们被一个螺旋旋转分开，表明AbrB与螺旋的一个面结合。为了研究spob在AbrB控制基因表达中的作用，我们采用Western blot方法检测了Spo+细胞和inspo细胞中AbrB蛋白的表达水平。在野生型细胞中，abb仅在营养生长期间被检测到，而inspooaccells在营养和静止生长期间都检测到高水平的AbrB。这些发现支持了一个模型，其中(i) spb负性影响AbrB的表达，以及（ii）过渡状态激活基因caand spovginsooacells的抑制是由于abb的组成表达，abb作为抑制因子。
InBacillus subtilistheabrBgene product negatively affects the transcription of some genes activated during the transition from vegetative to stationary phase of growth. Interaction of AbrB with the promoters of two such genes,spoVG, a sporulation gene, andtycA, an antibiotic biosynthesis gene, was studied by DNase I and hydroxyl radical footprinting. Two binding areas within the leader and promoter regions oftycAwere identified. InspoVGthe binding site is located at the A+T-rich region upstream of the promoter. Hydroxyl radical footprinting revealed that the AbrB-protected regions, in both thetycAandspoVGpromoters, are short A+T-rich regions that are separated by one helical turn, indicating that AbrB binds to one face of the helix. To examine the role ofspoOAin the expression ofabrB-controlled genes, the levels of AbrB protein in Spo+and inspoOAcells were determined by Western blot analysis. In wild-type cells AbrB was detected only during vegetative growth, whereas inspoOAcells a high level of AbrB was detected during both the vegetative and stationary phases of growth. These findings support a model in which (i)spoOAnegatively affectsabrBexpression, and (ii) the repression of the transition state-activated genestycAandspoVGinspoOAcells is due to constitutive expression of AbrB, which acts as a repressor.