STRUCTURAL STUDIES OF RNA POLYMERASE COMPLEXES

RNA聚合酶是细菌基因表达和调控的中心酶。最近，该实验室解决了核心RNAP(酶的过程形式)的X射线晶体结构，为后续该酶与其他亚基和配体相互作用的结构研究开辟了一条道路。这项建议的总体目标是了解与酶结构有关的转录机制。全酶结构的揭示将为Sigma因子如何使RNAP获得启动子专一性、启动转录和调节酶的基因抑制物提供更大的洞察力，将增加我们目前对转录机制的理解。这些结构也与针对细菌病原体的抗生设计的医学研究极其相关。这一建议将通过核心RNAP的X射线结晶学完成，其中包括以下因素：1)看家西格玛因子(SIgA)；2)起始核苷酸三磷酸(ATP)；3)二核苷酸(APU)；以及4)抗生素利福平和链溶菌素。

RNA polymerase is the central enzyme of gene expression and regulation in bacteria. Recently this laboratory has solved the X-ray crystal structure of core RNAP (the processive form of the enzyme) opening a path for subsequent structural studies of this enzyme's interaction with additional subunits and ligands. The overall goal of this proposal is to understand the mechanism of transcription in relation to the structure of the enzyme. Revelation of the holoenzyme structure would add great insight to how the sigma factor allows RNAP to acquire promoter specificity, initiate transcription and regulate gene inhibitors of the enzyme, will increase our current understanding of the transcription mechanisms. These structures are also extremely relevant to medical research for anti-biotic design against bacterial pathogens. This proposal will be accomplished by X-ray crystallography of core RNAP complexed with the following factors: 1) the housekeeping sigma factor (SigA); 2) an initiating nucleotide tri- phosphate, (ATP); 3) a dinucleotide (ApU) and 4) the antibiotics rifampican and streptolydigin.