A downstream-element-binding factor facilitates assembly of a functional preinitiation complex at the simian virus 40 major late promoter.
A downstream-element-binding factor facilitates assembly of a functional preinitiation complex at the simian virus 40 major late promoter.
复制标题
下游元件结合因子有助于在猿猴病毒 40 主要晚期启动子处组装功能性预起始复合物。
DOI：
10.1128/mcb.10.7.3635-3645.1990
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发表时间：
1990
影响因子：
5.3
通讯作者：
Dynan,WS
中科院分区：
文献类型：
--
作者：
Ayer,DE;Dynan,WS
最近的工作表明，许多真核RNA聚合酶II识别的启动子都含有位于转录起始点下游的必要序列。我们在这里表明，以猴病毒40主要晚期起始点下游28个碱基对为中心的启动子元件的活性似乎是由DNA结合蛋白介导的，该蛋白是通过亲和层析从HeLa细胞核提取液中分离出来的。在缺乏转录机制的其他组件的情况下，蛋白质与其识别序列特异性地但弱地结合，Kd值约为10-8M。动力学数据分析表明，下游元件的突变减少了在启动子上组装的功能性预引发复合体的数量，而不显著改变一半复合体组装所需的时间。这表明，在没有下游激活蛋白的情况下，预引发复合体至少部分组装好了，但在转录上没有活性。
Recent work has shown that many promoters recognized by eucaryotic RNA polymerase II contain essential sequences located downstream of the transcriptional initiation site. We show here that the activity of a promoter element centered 28 base pairs downstream of the simian virus 40 major late initiation site appears to be mediated by a DNA-binding protein, which was isolated by affinity chromatography from HeLa cell nuclear extracts. In the absence of the other components of the transcriptional machinery, the protein bound specifically but weakly to its recognition sequence, with aKdof approximately 10–8M. Analysis of kinetic data showed that mutation of the downstream element decreased the number of functional preinitiation complexes assembled at the promoter without significantly altering the time required for half the complexes to assemble. This suggests that in the absence of the downstream activating protein, preinitiation complexes are at least partially assembled but are not transcriptionally competent.