Bagby S, Mal T K, Liu D, Raddatz E, Nakatani Y, Ikura M
Division of Molecular Biology, Ontario Cancer Institute, Department of Medical Biophysics, University of Toronto, 610 University Avenue, Toronto, Ont., Canada.
FEBS Lett. 2000 Feb 25;468(2-3):149-54. doi: 10.1016/s0014-5793(00)01213-8.
TATA box binding protein (TBP)-promoter interaction nucleates assembly of the RNA polymerase II transcription initiation complex. Transcription factor IIA (TFIIA) stabilizes the TBP-promoter complex whereas the N-terminal domain of the largest TAF(II) inhibits TBP-promoter interaction. We have mapped the interaction sites on TBP of Drosophila TAF(II)230 and yeast TFIIA (comprising two subunits, TOA1 and TOA2), using nuclear magnetic resonance (NMR), and also report structural evidence that subdomain II of the TAF(II)230 N-terminal inhibitory domain and TFIIA have overlapping binding sites on the convex surface of TBP. Together with previous mutational and biochemical data, our NMR results indicate that subdomain II augments subdomain I-mediated inhibition of TBP function by blocking TBP-TFIIA interaction.
TATA 框结合蛋白（TBP）与启动子的相互作用引发了 RNA 聚合酶 II 转录起始复合物的组装。转录因子 IIA（TFIIA）可稳定 TBP - 启动子复合物，而最大的 TAF（II）的 N 端结构域则抑制 TBP - 启动子相互作用。我们利用核磁共振（NMR）技术绘制了果蝇 TAF（II）230 和酵母 TFIIA（由两个亚基 TOA1 和 TOA2 组成）在 TBP 上的相互作用位点，并且还报告了结构证据，表明 TAF（II）230 N 端抑制结构域的亚结构域 II 和 TFIIA 在 TBP 的凸面上具有重叠的结合位点。结合先前的突变和生化数据，我们的 NMR 结果表明，亚结构域 II 通过阻断 TBP - TFIIA 相互作用增强了亚结构域 I 介导的对 TBP 功能的抑制作用。
