Structural investigation of Helicobacter pylori transcription regulator NikR

描述（由申请人提供）：幽门螺杆菌是引起消化性溃疡的细菌病原体，与胃肠道癌症患病率增加有关。镍依赖性调节蛋白HpNikR位于调节网络的中心，该网络对幽门螺杆菌在胃腔附近的酸性环境中生存和在胃粘膜上皮附近的中性pH环境中茁壮成长的能力至关重要。本提案的目的是使用互补的实验和计算技术来确定HpNikR功能的结构和机械细节。在Aim 1中，目标是在中性pH下对载子和镍结合形式的HpNikR进行结构表征，确定与其一系列DNA操作子结合的HpNikR的三维结构，并评估载子和镍结合形式的HpNikR的寡聚状态。在Aim 2中，目的是检查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。阐明这些关于HpNikR的细节将有助于了解遗传调控途径在幽门螺杆菌致病性中的功能作用。

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.