Deciphering the Mechanisms of Pathogenic Ferrous Iron Acquisition and Eukaryotic Post-Translational Arginylation

项目摘要 Mira的这项建议旨在解决两个鲜为人知的蛋白质系统的关键知识空白。 它们与健康和人类疾病有关。为了实现这一建议，设计的研究结合了 结构、无机和生化方法，具有创新的金属中心观点，即 必需的，但主要仍未对这些蛋白质进行研究。第一个提出的研究体系是 亚铁(Fe2+)铁摄取(FeO)系统，几乎存在于所有细菌中，被病原体用来 在哺乳动物宿主中建立感染。以前对FeO的研究要么太大，要么太小 这导致了对机制的理解支离破碎，缺乏对机制的深入了解。这 Proposal概述了在蛋白质水平上研究FeO系统的综合方法。利用 结构、光谱分析和生化分析，这一建议旨在描绘出 原核Fe2+转运，这将使未来的研究人员能够探索紧迫但具有广泛影响的 FeO可能被利用来对抗细菌的毒力。第二个建议的学习系统 重点是精氨酸转移酶(称为ATE1s)，这是一种使N端精氨酸化的酶 多肽或蛋白质，随后通过泛素-蛋白酶体系统触发它们的降解。正常 血管紧张素转换酶1功能对神经发生和心血管发育至关重要，但结构和机制 ATE1介导的精氨酸化的细节非常缺乏，阻止了该系统的靶向治疗 干预。令人兴奋的结果表明，ATE1可能是含铁的酶，但铁在其中的作用 系统仍然未知。该提案旨在描述ATE1的结构和机制，包括 铁在这些酶中的潜在调节作用。为了实现这一目标，这项提议将蛋白质- 水平结构、生化和光谱方法阐明ATE1s的精氨酸化机制， 并解决铁是如何控制这个过程的。一旦确定，这种分子水平的细节将是无价的 设计针对ATE1的小分子进行干预。总而言之，这项提案的结果保持了 承诺帮助开发治疗方法，以消除细菌的毒性，并治疗神经性和 心血管疾病。

Project Summary This MIRA proposal aims to solve critical gaps in knowledge of two poorly understood protein systems that are linked to health and human disease. To accomplish this proposal, the designed studies combine structural, inorganic, and biochemical approaches with an innovative metallocentric point of view that is essential yet has remained chiefly unexplored for these proteins. The first proposed system of study is the ferrous (Fe2+) iron uptake (Feo) system, which is present in nearly all bacteria and is used by pathogens to establish infection in mammalian hosts. Previous studies on Feo have either been too large or too small in scope, leading to a fragmented and inconclusive understanding with little insight into mechanism. This proposal outlines a comprehensive approach to study the Feo system at the protein level. Leveraging structural, spectroscopic, and biochemical analyses, this proposal aims to delineate the mechanism of prokaryotic Fe2+ transport, which will position future researchers to explore the urgent but broadly impactful possibility that Feo may be exploited to combat bacterial virulence. The second proposed system of study focuses on the arginine transferases (known as ATE1s), which are enzymes that arginylate the N-terminus of peptides or proteins, subsequently triggering their degradation via the ubiquitin-proteasome system. Normal ATE1 function is critical for neurogenesis and cardiovascular development, but structural and mechanistic details of ATE1-mediated arginylation are sorely lacking, prohibiting the targeting of this system for therapeutic intervention. Exciting results indicate ATE1s may be iron-containing enzymes, but the function of iron in this system remains unknown. This proposal aims to delineate the structure and mechanism of ATE1s, including the potential regulatory role of iron in these enzymes. To achieve this goal, this proposal combines protein- level structural, biochemical, and spectroscopic methods to elucidate the arginylation mechanism of ATE1s, and to resolve how iron controls this process. Once determined, this molecular-level detail will be invaluable to design small molecules that target ATE1 for intervention. Combined, the results from this proposal hold the promise to aid in the development of therapeutics to abrogate bacterial virulence and to treat neurological and cardiovascular diseases.