INITIAL SOLUTION X-RAY SCATTERING STUDIES ON RNA POLYMERASE II-TBP-TFIIB-TFIIF-P

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来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 转录是基因表达途径的第一步，也是基因表达的关键控制点。 真核细胞中基因表达转录的中心酶是RNA聚合酶II（pol II），其需要许多辅助因子，称为通用转录因子（TF），用于识别启动子并特异性地启动转录。Pol II通过其与一般转录因子的相互作用充当转录起始和延伸复合物的组装平台。在近原子分辨率下与pol II共结晶的一般转录因子TFIIB的近原子分辨率结构对转录起始过程的机制给出了意想不到的见解。我们还研究了pol II与TBP、TFIIB、TFIIF和启动子DNA形成的转录起始复合物。 结合结构信息以及生物化学证据，我们提出了一个模型的基础转录起始复合物可能看起来像什么，但我们迄今没有直接的结构证据来证实这个模型。

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. Transcription is the first step and the key control point in the pathway of gene expression. The central enzyme in transcription for gene expression in eukaryotic cells is RNA polymerase II (pol II), which requires a number of accessory factors, referred to as general transcription factors (TF) for recognizing a promoter and specifically initiating transcription. Pol II serves as a platform for the assembly of transcriptional initiation and elongation complexes, through its interactions with the general transcription factors. The near atomic- resolution structure of the general transcription factor TFIIB co- crystallized with pol II at near atomic-resolution has given unexpected insight into the mechanism of the transcription initiation process. We have also studied the transcriptional initiation complexes formed pol II with TBP, TFIIB, TFIIF, and promoter DNA. Combining the structural information as well as biochemical evidence we propose a model for what the basal transcription initiation complex may look like, however we have so far no direct structural evidence to confirm this model.