Structural investigation of Helicobacter pylori transcription regulator NikR

描述（由申请人提供）：幽门螺杆菌是导致消化性溃疡的细菌病原体，与胃肠道癌症的发病率增加有关。镍依赖性调节蛋白HpNikR位于调节网络的中心，对H.幽门螺杆菌既能在胃腔附近的酸性环境中生存，又能在胃粘膜上皮层附近的中性pH环境中生长。该提案的目的是使用互补的实验和计算技术来确定HpNikR功能的结构和机制细节。在目的1中，目标是在中性pH下对载脂蛋白和镍结合形式的HpNikR进行结构表征，确定与其一系列DNA操纵子结合的HpNikR的三维结构，以及评估载脂蛋白和镍结合形式的HpNikR的低聚状态。在目标2中，目标是检查HpNikR中的镍配位位点，并使用计算和光谱方法研究特定氨基酸在DNA结合亲和力中的作用。阐明HpNikR的这些细节将提高对H. pylori致病性 公共卫生相关性：人类胃组织被致病菌幽门螺杆菌感染与消化性溃疡和胃癌和肠癌发病率增加有关。调节蛋白HpNikR是H.幽门螺杆菌在人类胃中茁壮成长并发挥作用。本研究的目的是深入了解HpNikR的结构和功能，以及它在H. pylori毒力

DESCRIPTION (provided by applicant): Helicobacter pylori is the bacterial pathogen that causes peptic ulcers and has been linked to increased prevalence of gastrointestinal cancers. The nickel-dependent regulatory protein, HpNikR, sits at the center of the regulatory network that is vital to ability of H. pylori to both survive in the acidic environment near the gastric lumen and to thrive in the neutral pH environment near the epithelial layer of the gastric mucous membrane. The objective of this proposal is to use complementary experimental and computational techniques to determine structural and mechanistic details of the function of HpNikR. In Aim 1, the goals are the structural characterization of HpNikR at neutral pH for the apo- and nickel-bound forms, determination of three dimensional structures of HpNikR bound to a series of its DNA operons, and assessment of the oligomeric state of HpNikR in the apo- and nickel-bound forms. In Aim 2, the objectives are the examination of the nickel coordination sites in HpNikR and investigation of the role of specific amino acids in DNA-binding affinity using computational and spectroscopic methods. Elucidation of these details about HpNikR will improve understanding of the functional role of genetic regulatory pathways in H. pylori pathogenicity. PUBLIC HEALTH RELEVANCE: Infections of human gastric tissue by the pathogenic bacteria Helicobacter pylori are associated with peptic ulcers and increased prevalence of stomach and intestinal cancers. The regulatory protein HpNikR is central to the ability of H. pylori to thrive and function in the human stomach. The goal of this research is to gain insight into the structure and function of HpNikR, and the roles it plays in H. pylori virulence.