Mitra A, An G
Institute of Biological Chemistry, Washington State University, Pullman 99164-6340.
Mol Gen Genet. 1989 Jan;215(2):294-9. doi: 10.1007/BF00339731.
Fine deletion mutants were generated in the upstream control region of the nopaline synthase (nos) promoter to define the position and role of upstream regulatory elements. The results indicated that the 8 bp sequence (CAGAAACC) at -106/-113 and its inverted repeat (GGTTTCTG) at -140/-147 are important for promoter function. The downstream element appears more important than the upstream element since deletion of the former reduced promoter activity more significantly than deletion of the latter. Deletion of the element alone, however, did not abolish promoter function, whereas, deletion of the 10 bp potential Z-DNA-forming (Z) element located between the repeat elements nullified promoter activity. Therefore, it appears that the Z element is an essential upstream regulator and the repeated elements are upstream modulators of the nos promoter. These elements are functionally distinct since alteration of stereospecificity or insertion of short oligonucleotides between the elements did not significantly influence promoter activity. These regulatory elements were unable to function from 200 bp upstream of the CCAAT-TATA box region.
在胭脂碱合成酶（nos）启动子的上游控制区产生精细缺失突变体，以确定上游调控元件的位置和作用。结果表明，位于-106/-113的8 bp序列（CAGAAACC）及其位于-140/-147的反向重复序列（GGTTTCTG）对启动子功能很重要。下游元件似乎比上游元件更重要，因为前者的缺失比后者的缺失更显著地降低了启动子活性。然而，单独缺失该元件并没有消除启动子功能，而位于重复元件之间的10 bp潜在Z-DNA形成（Z）元件的缺失则使启动子活性丧失。因此，Z元件似乎是一个必需的上游调节因子，而重复元件是nos启动子的上游调节因子。这些元件在功能上是不同的，因为立体特异性的改变或元件之间短寡核苷酸的插入并没有显著影响启动子活性。这些调控元件在CCAAT-TATA框区域上游200 bp处无法发挥作用。
