nisZ启动子结构与功能的研究

Studies on Structure and Function of nis Z Promoter

应用β Glucuronidase基因 (gusA)作为报告基因 ,通过定点突变方法分别缺失nisZ编码区上游两个启动子结构 (promoter1和promoter2 )中的一个 ,发现只有靠近编码区的promoter2是nisZ启动子诱导表达所必需。将promoter2中 1 0区及其上游的一个碱基突变为乳酸菌中典型的组成型启动子的 1 0区结构 ,该改变使nisZ启动子诱导功能下降 ;将promoter2的 1 0区和 35区的间隔区由 2 0个碱基缺失突变为 1 7个碱基 ,则nisZ启动子失去诱导功能。

Glucuronidase( gus A) gene was used as reporter gene for analyzing nis Z promoter. Two promoter regions(promoter1 and promoter2) upstream of nis Z code region were deleted respectively by site directed mutagenesis. Only promoter2, the promoter region near the code region, was involved in the induction and expression of nis Z promoter. nis Z promoter induction level was reduced when 10 region of promoter2 was mutated to a constitutive 10 region. nis Z promoter lost function when the spacer of the 10 and 35 regions of promoter2 was reduced from 20bp to 17bp. The results indicate the spacer play an important role on induction and expression of nis Z promoter.