Structural studies of the eukaryotic transcription

描述（由申请人提供）：基因转录的调节是 在细胞分化和发育的过程中是必不可少的， 生物体，以及每个细胞在不断变化的环境中的生存 条件基因转录及其调控的重要性是 强调了无数的人类疾病，造成的故障， 参与这个细胞过程的分子成分。基因起始 真核生物中的转录始于TFIID的结合，TFIID含有 TATA结合蛋白（TBP）与DNA核心启动子的结合，以及随之而来的 一般转录机制的组装。六个一般的转录 因子和RNA Pol H构成了最小的蛋白质组装， 转录，总计数百万道尔顿。TFIID还参与了 与基因特异性激活剂的相互作用。我们的最终目标是 了解真核生物转录起始机制如何组装， 功能和基因转录调控的结构机制。到 为此，我们将描述TFIID的结构及其与 使用冷冻电子显微镜观察其他一般因素和活化剂， 单粒子图像重建我们最近得到了一个初步的 TFHD及其与全长TFILA和TFIIB复合物在35 A下结构 通过阴性染色进行解析，并通过抗体定位， TBP在复杂的。我们的当务之急之一是获得一个3D 以更好的分辨率重建冷冻水合的人TFIID复合物 25 A。我们感兴趣的是遵循结构组装， 这种复杂的机器通过生成介质的构象变化 越来越大的复合物的分辨率结构，TFIID作为 中央核心我们的最终目标是描述 转录调控的相互作用的一般转录 机械与活化剂为此，我们将研究由以下物质形成的复合物： TFIID与通用激活剂Sp 1。

DESCRIPTION (provided by applicant): Regulation of gene transcription is essential in the process of cell differentiation and development of the organism, as well as for the survival of each cell in changing environmental conditions. The importance of gene transcription and its regulation is underlined by the myriad of human disorders that result from the malfunction of the molecular components involved in this cellular process. Initiation of gene transcription in eukaryotes starts with the binding of TFIID, containing the TATA binding protein (TBP), to the DNA core promoter, and the consequent assembly of the general transcriptional machinery. Six general transcription factors and RNA Pol H constitute the minimal protein assembly for transcription, adding up to several million Daltons. TFIID is also involved in the interaction with gene-specific activators. Our ultimate goal is to understand how the eukaryotic transcription initiation machinery assembles and functions, and the structural mechanisms for gene transcription regulation. To this end we will characterize the structure of TFIID and its interaction with other general factors and with activators using cryo-electron microscopy and single-particle image reconstruction. We have recently obtained an initial structure of TFHD and its complex with full length TFILA and TFIIB at 35 A resolution by negative stain, and localized, by antibody mapping, the position of TBP within the complex. One of our immediate priorities is to obtain a 3-D reconstruction of frozen-hydrated human TFIID complexes at a resolution better than 25 A. We are interested in following the structural assembly and conformational changes of this complex machinery by generating medium resolution structures of increasingly larger complexes, with TFIID as the central core. Our final goal is to characterize the structural basis of transcription regulation by the interaction of the general transcriptional machinery with activators. To this end we will study the complexes formed by TFIID with the general activator Sp 1.