Zeng Xianmin, Galinier Anne, Saxild Hans H
Department of Microbiology, Technical University of Denmark, Building 301, DK-2800 Lyngby, Denmark1.
Institut de Biologie et Chimie des Protéines, CNRS, 7 Passage du Vercors, F-69376 Lyon, Cedex 07, France2.
Microbiology (Reading). 2000 Nov;146 ( Pt 11):2901-2908. doi: 10.1099/00221287-146-11-2901.
Expression of the Bacillus subtilis dra-nupC-pdp operon is subject to catabolite repression by glucose. It was shown that a cis-acting catabolite-responsive element (CRE) sequence located 64 bp downstream of the transcription-start site mediated catabolite repression of the dra-nupC-pdp operon as it does for many other B. subtilis genes. Point mutations in the CRE sequence caused the loss of catabolite repression of the operon. Catabolite repression of dra-nupC-pdp expression was relieved in a ccpA mutant and was found to be dependent on both HPr and the HPr-like protein Crh. Furthermore, a transcription-repair coupling factor, Mfd, was also found to be involved in the glucose repression of dra-nupC-pdp expression. By the use of in vitro gel mobility shift analysis, a specific HPr-P dependent binding of CcpA to the dra CRE site was demonstrated.
枯草芽孢杆菌dra - nupC - pdp操纵子的表达受葡萄糖的分解代谢物阻遏。研究表明，位于转录起始位点下游64 bp处的顺式作用分解代谢物响应元件（CRE）序列介导了dra - nupC - pdp操纵子的分解代谢物阻遏，就像对许多其他枯草芽孢杆菌基因一样。CRE序列中的点突变导致操纵子分解代谢物阻遏的丧失。dra - nupC - pdp表达的分解代谢物阻遏在ccpA突变体中得到缓解，并且发现其依赖于HPr和HPr样蛋白Crh。此外，还发现转录修复偶联因子Mfd也参与了dra - nupC - pdp表达的葡萄糖阻遏。通过体外凝胶迁移率变动分析，证明了CcpA与dra CRE位点存在特异性的HPr - P依赖性结合。
