CONFORMATIONAL CHANGE OF TFIIB DURING TRANSCRIPTIONAL INITIATION

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 TFIIB在RNA聚合酶II介导的转录启动中起着关键作用。TFIIB作为连接RNA聚合酶II和启动子的桥梁，协调准确的起始位点选择。TFIIB由328个氨基酸组成，可分为N-末端锌带结构域、B-Finger结构域、Linker结构域和C-末端核心结构域。生化数据已经暗示了启动子结合前后的构象变化。在我们的RNA聚合酶II-TFIIB晶体结构中，我们观察到了一种类似于启动子结合状态的构象状态，即使晶体结构中没有启动子。我们推测，结晶条件可能解释了通常通过启动子结合完成的构象变化。因此，我们建议研究TFIIB在不同缓冲条件下的构象状态，并将其与TFIIB启动子结合的构象进行比较。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. TFIIB plays a key role in RNA polymerase II mediated transcriptional initiation. TFIIB functions as a bridge that links together the RNA polymerase II and promoter and orchestrates the accurate start site selection. TFIIB, composed of 328 amino acids, can be divided into several independently folded domains including an N-terminal Zinc-ribbon domain, a B-finger domain, a Linker domain and a C-terminal Core domain. Biochemical data have implicated an conformational change before and after promoter binding. In our RNA polymerase II - TFIIB crystal structure, we observed a conformation state that is similar to the promoter-bound state even in absence of promoter in the crystal structure. We reason that the crystallization condition may account for the conformational change that is normally accomplished through promoter binding. So we propose to investigate the conformation states of TFIIB under different buffer conditions and to compare them with the promoter-bound conformation of TFIIB.