Oelgeschläger T, Chiang C M, Roeder R G
Laboratory of Biochemistry and Molecular Biology, The Rockefeller University, New York 10021, USA.
Nature. 1996 Aug 22;382(6593):735-8. doi: 10.1038/382735a0.
Transcription factor TFIID is a multiprotein complex composed of a TATA-box-binding subunit, TBP, and several tightly associated factors (TAFs). Human TFIID-promoter interactions are restricted to the TATA-box region on most core promoters but extend over a large promoter region downstream of the TATA box and the transcription start site on the Ad2ML promoter. TFIID downstream interactions are thought to be functionally relevant because they can be induced by transcriptional activators, which in some cases requires TFIIA, result in stabilization of the TFIID-promoter complex, and correlate with increased recruitment of the remaining general transcription factors. Here we examine the topological organization of human TFIID complexes bound to the Ad2ML promoter. Our data provide insight into the relative disposition of DNA and several TFIID subunits, as well as evidence for DNA wrapping by TFIID, and suggest a direct role of TFIIA in the stable positioning of promoter DNA relative to TAFs.
转录因子TFIID是一种多蛋白复合物，由一个TATA框结合亚基TBP和几个紧密相关的因子（TAFs）组成。在大多数核心启动子上，人类TFIID与启动子的相互作用局限于TATA框区域，但在Ad2ML启动子上，这种相互作用会延伸到TATA框下游的大片启动子区域以及转录起始位点。TFIID下游的相互作用被认为具有功能相关性，因为它们可被转录激活因子诱导，在某些情况下这需要TFIIA，会导致TFIID - 启动子复合物的稳定，并与其余通用转录因子的募集增加相关。在这里，我们研究了与Ad2ML启动子结合的人类TFIID复合物的拓扑结构。我们的数据深入了解了DNA与几个TFIID亚基的相对位置，以及TFIID包裹DNA的证据，并表明TFIIA在启动子DNA相对于TAFs的稳定定位中起直接作用。
