CATABOLITE ACTIVATOR PROTEIN - ALPHACTD - SIGMA REGION4 - DNA COMPLEX

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。子项目及 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。 DNA转录成RNA是蛋白质合成所需信息传递的中心过程。原核生物转录的研究为理解所有生命系统中的转录事件提供了一个简单的模型。这项工作的目标是表征参与转录起始在I类分解代谢物激活蛋白（CAP）依赖的启动子在细菌中的结构因子。为此，包含CAP，DNA和RNA聚合酶（<$-CTD）的亚基的C-末端结构域的晶体结构，这是最近在本实验室解决的，扩展到包括<$？RNA聚合酶亚基第四区还是？R4）。那个... RNA聚合酶的R4被认为在转录起始时与CTD和DNA特异性接触。因此，CAP、DNA、CTD和CTD的复合物，R4已结晶。数据是以NSLS X25至3.5分辨率收集的。 我们现在有了含有溴尿苷衍生DNA的晶体。溴原子，用于同晶置换，并与部分分子置换溶液相结合，将允许DNA在晶体中的可靠放置。σ区4的内含物这个晶体复合物桥接了CAP DNA结构和RNA聚合酶结构之间的结构信息中的差距。该结构的完成将提供CAP对细菌转录激活的完整描述。

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. The transcription of DNA into RNA is a central process in the transfer of information required for protein synthesis. The study of transcription in prokaryotes provides a simple model for understanding transcription events in all living systems. The goal of this work is to characterize the structural factors involved in transcription initiation at Class I catabolite activator protein (CAP)-dependent promoters in bacteria. To this end, a crystal structure containing CAP, DNA and the C-Terminal Domain of the ¿}¿¿ subunit of RNA polymerase (¿}¿¿-CTD), which has been recently solved in this lab, is expanded to include the C-terminus of the ¿?¿¿ subunit of RNA polymerase (¿?¿¿ Region 4 or ¿?¿¿-R4). The ¿?¿¿-R4 of RNA polymerase is thought to make specific contacts with ¿}¿¿-CTD and DNA in transcription initiation. Thus, a complex of CAP, DNA, ¿}¿¿-CTD, and ¿?¿¿-R4 has been crystallized. Data has been collected on NSLS X25 to 3.5 ¿¿¿ resolution. We now have crystals of containing Bromo-uridine derivatized DNA. The Bromine atoms, used in isomorphous replacement and combined with a partial molecular replacement solution will permit confident placement of the DNA in the crystal. The inclusion of sigma region 4 this crystal complex bridges the gap in structural information between CAP ¿¿¿¿¿" DNA structures and RNA polymerase structures. Completion of this structure will provide a complete picture of bacterial transcription activation by CAP.