CONFORMATIONAL CHANGE OF TFIIB DURING TRANSCRIPTIONAL INITIATION

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得主要资金， 因此可以在其他CRISP条目中表示。列出的机构是 中心，不一定是研究者的机构。 TFIIB在RNA聚合酶II介导的转录起始中起关键作用。TFIIB作为将RNA聚合酶II和启动子连接在一起的桥梁发挥作用，并协调准确的起始位点选择。TFIIB由328个氨基酸组成，可分为几个独立折叠的结构域，包括N端锌带结构域、B指结构域、接头结构域和C端核心结构域。生物化学数据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，我们观察到即使在晶体结构中不存在启动子的情况下也与启动子结合状态相似的构象状态。我们的理由，结晶条件可能占构象变化，通常是通过启动子结合完成。 因此，我们建议研究TFIIB在不同缓冲液条件下的构象状态，并将其与TFIIB的启动子结合构象进行比较。

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.