Peschel A, Augustin J, Kupke T, Stevanovic S, Götz F
Mikrobielle Genetik, Universität Tübingen, Germany.
Mol Microbiol. 1993 Jul;9(1):31-9. doi: 10.1111/j.1365-2958.1993.tb01666.x.
We investigated the role of epiQ in the biosynthesis of the lantibiotic epidermin. epiQ was essential for epidermin production. It was shown that EpiQ controls epidermin production by transcriptionally activating the epiA promoter, used for transcription of most of the epidermin biosynthetic genes. Additional copies of epiQ increased epidermin production in the epidermin-producing wild-type strain Staphylococcus epidermidis Tü3298. The epiA promoter region was characterized by primer extension analysis. Two inverted repeats, putative operator sites for EpiQ binding, are located upstream of the -35 region and one is localized downstream of the -10 region. Crude protein extracts from S. epidermidis Tü3298 and epiQ expressing Escherichia coli cells led to gel mobility shifts of a DNA fragment bearing the inverted repeat which is located immediately upstream of the -35 region. DNA fragments bearing the other two inverted repeats were not shifted. The epiQ gene product could be detected by overexpression in the E. coli T7 system using antiserum raised against synthetic peptides of EpiQ. Furthermore, EpiQ, like other DNA-binding proteins, was shown to bind strongly to heparin sepharose.
我们研究了epiQ在羊毛硫抗生素表皮菌素生物合成中的作用。epiQ对表皮菌素的产生至关重要。结果表明，EpiQ通过转录激活epiA启动子来控制表皮菌素的产生，epiA启动子用于转录大多数表皮菌素生物合成基因。在产生表皮菌素的野生型菌株表皮葡萄球菌Tü3298中，额外的epiQ拷贝增加了表皮菌素的产量。通过引物延伸分析对epiA启动子区域进行了表征。两个反向重复序列，推测为EpiQ结合的操纵位点，位于-35区域上游，一个位于-10区域下游。来自表皮葡萄球菌Tü3298和表达epiQ的大肠杆菌细胞的粗蛋白提取物导致携带位于-35区域紧邻上游的反向重复序列的DNA片段发生凝胶迁移率变动。携带其他两个反向重复序列的DNA片段未发生迁移。使用针对EpiQ合成肽产生的抗血清，通过在大肠杆菌T7系统中过表达可以检测到epiQ基因产物。此外，与其他DNA结合蛋白一样，EpiQ被证明与肝素琼脂糖有很强的结合力。
