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

项目摘要 MIRA的这一提议旨在解决两个知之甚少的蛋白质系统知识的关键空白 与健康和人类疾病有关的疾病。为了完成这一建议，设计的研究联合收割机 结构，无机和生物化学的方法，具有创新的生物中心的观点， 然而，这些蛋白质的主要未开发。第一个提议的研究系统是 亚铁（Fe 2+）铁吸收（FeO）系统，几乎存在于所有细菌中，并被病原体用于 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， 范围，导致对机制缺乏深入了解的零散和不确定的理解。这 该提案概述了在蛋白质水平上研究FeO系统的综合方法。利用 结构，光谱和生物化学分析，这项建议的目的是描绘机制， 原核Fe 2+转运，这将使未来的研究人员能够探索迫切但广泛影响的 FeO可能被用来对抗细菌的毒力。第二种研究方法 专注于精氨酸转移酶（称为ATE 1），这是一种酶， 肽或蛋白质，随后通过泛素-蛋白酶体系统触发其降解。正常 ATE 1功能对于神经发生和心血管发育至关重要，但结构和机制 ATE 1介导的腺苷酸化的细节非常缺乏，这阻碍了该系统用于治疗的靶向。 干预令人兴奋的结果表明，ATE 1可能是含铁的酶，但铁在这一过程中的作用 系统仍然未知。本建议旨在描述ATE 1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，该提案结合了蛋白质- 水平的结构，生物化学和光谱方法来阐明ATE 1的酰基化机制， 并解决铁如何控制这一过程。一旦确定，这种分子水平的细节将是无价的， 设计靶向ATE 1的小分子进行干预。综合起来，这项提案的结果表明， 有望帮助开发消除细菌毒力和治疗神经和 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.