Biological roles and mechanisms of nitric oxide reactions with iron-sulfur cluster transcriptional regulators

一氧化氮与铁硫簇转录调节因子反应的生物学作用和机制

基本信息

批准号：
BB/J003247/1
负责人：
Nicolas Le Brun
金额：
$ 44.93万
依托单位：
University of East Anglia
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2012
资助国家：
英国
起止时间：
2012 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=BB%2FJ003247%2F1
关键词：
Biological roles mechanisms nitric oxide

项目摘要

Nitric oxide is a poisonous molecule that is generated by soil bacteria and in our bodies as a defence against pathogenic organisms trying to establish infection. One of the major ways by which nitric oxide exerts its toxic effects is through reaction with a widespread group of proteins that contain a type of cofactor made from both iron and sulfur (called an iron-sulfur cluster). Members of this group play crucial roles in a very wide range of cellular processes. To avoid nitric oxide toxicity, disease-causing (as well as benign) bacteria have evolved protective systems that function to detoxify nitric oxide by removing it through chemical reaction. The fact that iron-sulfur cofactors are particularly sensitive to nitric oxide has been exploited in Nature, through the evolution of a number of regulatory proteins that themselves contain an iron-sulfur cluster and which function as biological switches, turning on the cellular nitric oxide detoxification response in the presence of nitric oxide. Despite the importance and widespread nature of the reaction of iron-sulfur clusters with NO, very little is known about this reaction process. This application is focussed on understanding how NO-responsive iron-sulfur cluster-containing regulators function. Here, we propose to investigate two such regulators (called WhiD and NsrR). One (WhiD) is a member of a family of proteins that are found only in a small number of bacteria (including Mycobacteria tuberculosis, the causative agent of tuberculosis, one of the world's major killers, and Streptomyces coelicolor, the source of many of the antibiotics currently in use in the clinic). Members of this protein family are known to play key roles in these bacteria in cell developmental processes associated with stress response, and are crucial for the ability of M. tuberculosis to survive in the inhospitable environment of a human host for years, in a dormant state that is highly resistant to antibiotics. The other (NsrR), is a member of a widely distributed but largely unstudied family of regulators. It functions as a primary NO sensor by controlling the cellular response to NO toxicity. Recent work in our laboratories has revealed important new insight into the nature of these regulatory proteins, including, for the first time, detailed mechanistic information about the reaction of a protein-bound iron-sulfur cluster with nitric oxide, leading to the formation of previously unreported products. We now propose to exploit these recent advances to explore, using a wide range of methods, the biochemistry of the reaction of NO with these proteins. This will reveal unprecedented mechanistic insight into how NO-sensing regulatory proteins function, and provide information that will be of general importance for all iron-sulfur protein NO reactions.

一氧化氮是一种有毒分子，由土壤细菌产生，在我们体内用于防御试图建立感染的病原生物。一氧化氮发挥毒性作用的主要方式之一是与一组广泛存在的蛋白质发生反应，这些蛋白质含有一种由铁和硫组成的辅助因子（称为铁硫簇）。该群体的成员在广泛的细胞过程中发挥着至关重要的作用。为了避免一氧化氮毒性，致病（以及良性）细菌进化出保护系统，通过化学反应去除一氧化氮，从而解毒。铁硫辅因子对一氧化氮特别敏感的事实已在自然界中得到利用，通过许多调节蛋白的进化，这些调节蛋白本身含有铁硫簇，并充当生物开关，开启细胞一氧化氮解毒一氧化氮存在下的反应。尽管铁硫簇与 NO 的反应非常重要且广泛，但人们对这一反应过程知之甚少。该应用的重点是了解 NO 响应性铁硫簇调节剂如何发挥作用。在这里，我们建议研究两个这样的监管机构（称为 WhiD 和 NsrR）。 WhiD 是仅在少数细菌中发现的蛋白质家族的成员（包括结核分枝杆菌，结核病的病原体，世界主要杀手之一，以及天蓝色链霉菌，许多细菌的来源）。目前临床上使用的抗生素）。众所周知，该蛋白质家族的成员在这些细菌与应激反应相关的细胞发育过程中发挥着关键作用，并且对于结核分枝杆菌在人类宿主的恶劣环境中以休眠状态生存多年的能力至关重要对抗生素具有高度耐药性。另一个（NsrR）是分布广泛但基本上未被研究的监管家族的成员。它通过控制细胞对 NO 毒性的反应，充当主要的 NO 传感器。我们实验室最近的工作揭示了对这些调节蛋白性质的重要新见解，包括首次提供有关蛋白质结合的铁硫簇与一氧化氮反应的详细机制信息，从而导致先前形成未报告的产品。我们现在建议利用这些最新进展，使用多种方法来探索 NO 与这些蛋白质反应的生物化学。这将揭示对 NO 传感调节蛋白如何发挥作用的前所未有的机制见解，并提供对所有铁硫蛋白 NO 反应具有普遍重要性的信息。