Lee D K, Wang K C, Roeder R G
Laboratory of Biochemistry and Molecular Biology, The Rockefeller University, New York, NY 10021, USA.
Nucleic Acids Res. 1997 Nov 1;25(21):4338-45. doi: 10.1093/nar/25.21.4338.
The binding of TFIID to the TATA element initiates assembly of a preinitiation complex and thus represents one of the most important steps for transcriptional regulation. The fact that the TATA binding protein (TBP), a subunit of TFIID, exclusively contacts the minor groove of the TATA element led us to ask whether the major groove of the TATA element plays any role in transcription initiation or its regulation. Our results show that modifications of the major groove of the TATA element in the adenovirus major late promoter have no effect on TFIID binding affinity or on transcription in a cell-free system reconstituted with purified factors. However, major groove modifications do decrease the levels of both basal and activator-mediated transcription in unfractionated nuclear extracts, indicating that the intact structure of the major groove of the TATA element is functionally important for transcription initiation in a more physiological context.
TFIID与TATA元件的结合启动了前起始复合物的组装，因此代表了转录调控中最重要的步骤之一。TFIID的一个亚基TATA结合蛋白（TBP）仅与TATA元件的小沟接触，这一事实促使我们探究TATA元件的大沟在转录起始或其调控中是否发挥任何作用。我们的结果表明，腺病毒主要晚期启动子中TATA元件大沟的修饰对TFIID结合亲和力或在用纯化因子重构的无细胞系统中的转录没有影响。然而，大沟修饰确实会降低未分级核提取物中基础转录和激活剂介导转录的水平，这表明在更生理的环境中，TATA元件大沟的完整结构对转录起始在功能上很重要。
