Transcription preinitiation complex assembly on the promoters of protein encoding genes is nucleated in vivo by TFIID composed of the TATA-box Binding Protein (TBP) and 13 TBP-associate factors (Tafs) providing regulatory and chromatin binding functions. Here we present the cryo-electron microscopy structure of promoter-bound yeast TFIID at a resolution better than 5 Å, except for a flexible domain. We position the crystal structures of several subunits and, in combination with cross-linking studies, describe the quaternary organization of TFIID. The compact tri lobed architecture is stabilized by a topologically closed Taf5-Taf6 tetramer. We confirm the unique subunit stoichiometry prevailing in TFIID and uncover a hexameric arrangement of Tafs containing a histone fold domain in the Twin lobe.

中文翻译：

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启动子结合的酵母TFIID的分子结构。

TFIID在体内编码蛋白质编码基因的启动子上的转录预起始复合物，该TFIID由TATA盒结合蛋白（TBP）和13种TBP相关因子（Tafs）组成，提供调节和染色质结合功能。在这里，我们提出了与启动子结合的酵母TFIID的低温电子显微镜结构，其分辨率优于5Å，除了柔性域。我们定位几个亚基的晶体结构，并与交联研究相结合，描述了TFIID的四级组织。紧凑的三叶架构通过拓扑封闭的Taf5-Taf6四聚体得以稳定。我们证实了在TFIID中普遍存在的独特的亚基化学计量，并揭示了在双叶中含有组蛋白折叠域的Tafs的六聚体排列。