Hutchings Matthew I, Hong Hee-Jeon, Leibovitz Emmanuelle, Sutcliffe Iain C, Buttner Mark J
Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Colney, Norwich NR4 7UH, United Kingdom.
J Bacteriol. 2006 Oct;188(20):7222-9. doi: 10.1128/JB.00818-06.
We have investigated the role of CseA in the sigma(E) cell envelope stress response of the gram-positive bacterium Streptomyces coelicolor. sigma(E) is an extracytoplasmic function RNA polymerase sigma factor required for normal cell envelope integrity in S. coelicolor. sigma(E) is encoded within a four-gene operon that also encodes CseA, a protein of unknown function, CseB, a response regulator and CseC, a transmembrane sensor histidine kinase (Cse represents control of sigma E). Previous work has shown that transcription of the sigE gene is completely dependent on the CseBC two-component system and that the CseBC-sigma(E) signal transduction system is induced by a wide variety of cell-wall-damaging agents. Here we address the role of CseA, a protein with no homologues outside the streptomycetes. We show that CseA is a novel lipoprotein localized to the extracytoplasmic face of the cell membrane and that loss of CseA results in upregulation of the sigE promoter.
我们研究了CseA在革兰氏阳性细菌天蓝色链霉菌的σ(E)细胞膜应激反应中的作用。σ(E)是一种胞外功能RNA聚合酶σ因子，是天蓝色链霉菌正常细胞膜完整性所必需的。σ(E)编码于一个四基因操纵子内，该操纵子还编码功能未知的蛋白质CseA、应答调节因子CseB和跨膜传感组氨酸激酶CseC（Cse代表σE的控制）。先前的研究表明，sigE基因的转录完全依赖于CseBC双组分系统，并且CseBC-σ(E)信号转导系统可被多种细胞壁损伤剂诱导。在此，我们探讨了CseA的作用，CseA是一种在链霉菌之外没有同源物的蛋白质。我们发现CseA是一种定位于细胞膜胞外表面的新型脂蛋白，并且CseA的缺失会导致sigE启动子上调。
