Structure-function analyses of siderophore biosynthetic enzymes

描述（由申请人提供）：铁载体是由细菌产生的低分子量铁螯合剂，用于从环境中吸收铁，并且通常是细菌毒力所需的。该实验室研究的长期目标是提供对铁载体生物合成途径中酶的详细机制和结构理解，这些途径是药物发现的目标。为此，我们建议研究参与从细菌铜绿假单胞菌产生铁载体绿脓菌螯铁蛋白和绿脓菌荧光素的非核糖体肽合成酶辅助酶。两个四种酶进行研究，异分支酸合酶（PchA）和异分支酸丙酮酸裂解酶（PchB），是理想的模型系统，使根本性的进展，了解替代反应途径的催化。鸟氨酸羟化酶（PvdA）的研究显示了新的黄素生物化学的承诺，和羟基鸟氨酸转化酶（PvdF）的第一个特征。我们将使用多方面的方法，包括酶动力学分析，结构生物学和计算酶学。 铜绿假单胞菌是一种危险的病原体，是易感宿主感染的常见原因，包括癌症和艾滋病患者、免疫缺陷患者、囊性纤维化患者、烧伤患者和其他高危个体，包括婴儿。这项工作的目标是提供对促进铜绿假单胞菌毒力的四种酶的基本了解，以便可以利用这些信息来产生新的抗菌药物。

DESCRIPTION (provided by applicant): Siderophores are low molecular weight iron chelators produced by bacteria to scavenge iron from the environment, and are frequently required for bacterial virulence. The long-term goal of the research in this laboratory is to provide a detailed mechanistic and structural understanding of enzymes in the siderophore biosynthetic pathways that are targets for drug discovery. Toward that end, we propose to investigate the nonribosomal peptide synthetase accessory enzymes that are involved in the production of the siderophores pyochelin and pyoverdin from the bacteria P. aeruginosa. Two of the four enzymes to be studied, the isochorismate synthase (PchA) and isochorismate-pyruvate lyase (PchB), are ideal model systems for making fundamental advances in understanding alternate reaction pathways for catalysis. The studies of the ornithine hydroxylase (PvdA) show promise for novel flavin biochemistry, and the first characterization of the hydroxyornithine transformylase (PvdF) is proposed. We will use a multifaceted approach that includes enzyme kinetic analysis, structural biology and computational enzymology. Narrative Pseudomonas aeruginosa is a dangerous pathogen that is a common cause of infections in susceptible hosts, including cancer and AIDS patients, those with immune deficiencies, cystic fibrosis patients, burn patients and other at risk individuals including infants. The goal of this work is to provide a fundamental understanding of four enzymes that promote virulence in P. aeruginosa so that this information can be exploited to generate new antimicrobial drugs.