Structure and function of a human TAFII250 double bromodomain module
Structure and function of a human TAFII250 double bromodomain module
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DOI：
10.1126/science.288.5470.1422
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发表时间：
2000-05-26
期刊：
影响因子：
56.9
通讯作者：
Tjian, R
中科院分区：
文献类型：
--
作者：
Jacobson, RH;Ladurner, AG;Tjian, R
TFIID是启动转录机制组装的大型多蛋白复合物。目前还不清楚当模板与核小体结合时，TFIID如何在体内识别启动子。这里，它表明，TAF（II）250，TFIID的最大亚基，含有两个串联的布罗莫结构域模块，选择性地结合到多乙酰化组蛋白H4肽。双布罗莫结构域的2.1埃晶体结构揭示了具有高度极化的表面电荷分布的两个并排的四螺旋束。每个束在其中心含有N-乙酰基赖氨酸结合口袋，这导致理想地适合于识别二乙酰化组蛋白H4尾的结构。因此，TFIID可以靶向特定的染色质结合的启动子，并可能在染色质识别中发挥作用。
TFIID is a large multiprotein complex that initiates assembly of the transcription machinery. It is unclear how TFIID recognizes promoters in vivo when templates are nucleosome-bound. Here, it is shown that TAF(II)250, the Largest subunit of TFIID, contains two tandem bromodomain modules that bind selectively to multiply acetylated histone H4 peptides. The 2.1 angstrom crystal structure of the double bromodomain reveals two side-by-side, four-helix bundles with a highly polarized surface charge distribution. Each bundle contains an N-epsilon-acetyllysine binding pocket at its center, which results in a structure ideally suited for recognition of diacetylated histone H4 tails. Thus, TFIID may be targeted to specific chromatin-bound promoters and may play a role in chromatin recognition.