Hoffmann A, Chiang C M, Oelgeschläger T, Xie X, Burley S K, Nakatani Y, Roeder R G
Laboratory of Biochemistry and Molecular Biology, The Rockefeller University, New York 10021, USA.
Nature. 1996 Mar 28;380(6572):356-9. doi: 10.1038/380356a0.
The general transcription factor TFIID nucleates initiation complex formation through direct core promoter binding, commits promoters within chromatin to transcription, and mediates the action of transcriptional activators, a phenomenon that may correlate with enhanced TFIID recruitment or conformational changes in TFIID-promoter complexes. Molecular studies of the multiprotein TFIID complex have identified a primary TATA binding subunit (TBP), TBP-associated factors (TAFs) that interact with and mediate the function of activators and intersubunit interactions but have yielded relatively little insight into the structural organization of the complex or the actual mechanism of transcriptional activation. Here we present biochemical evidence for the structural relevance of histone homologies in the human TFIID subunits hTAF80, hTAF31 and hTAF20/15. Together with analyses of native TFIID complexes and accompanying crystallographic studies, the results suggest that there is a histone octamer-like TAF complex within TFIID.
通用转录因子TFIID通过直接结合核心启动子来启动起始复合物的形成，使染色质中的启动子进行转录，并介导转录激活因子的作用，这一现象可能与TFIID募集增强或TFIID-启动子复合物的构象变化相关。对多蛋白TFIID复合物的分子研究已经鉴定出一个主要的TATA结合亚基（TBP）、与激活因子相互作用并介导其功能以及亚基间相互作用的TBP相关因子（TAFs），但对于该复合物的结构组织或转录激活的实际机制了解相对较少。在此，我们提供了关于人TFIID亚基hTAF80、hTAF31和hTAF20/15中组蛋白同源性结构相关性的生化证据。结合对天然TFIID复合物的分析及相关晶体学研究结果表明，TFIID中存在一个类似组蛋白八聚体的TAF复合物。
