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A new pathway for iron-sulfur cluster repair

铁硫簇修复的新途径

基本信息

批准号：
BB/L007673/1
负责人：
Nicolas Le Brun
金额：
$ 45.95万
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：
2014
资助国家：
英国
起止时间：
2014 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=BB%2FL007673%2F1
关键词：
new pathway iron sulfur cluster

项目摘要

Bacteria inhabit almost every environmental niche on Earth, including some that are so harsh that many other forms of life cannot survive. This success is at least in part due to the ability of bacteria to adapt to changes in environment, and this adaptation is rooted in their capacity to alter patterns of gene expression in response to external and internal cues. A key environmental parameter that is monitored by many bacteria is oxygen concentration. We are particularly interested in the bacterium Escherichia coli (E. coli). One of its remarkable properties is that it is able to thrive both in the presence and absence of oxygen. To do this it has to dramatically alter its metabolism, but this has consequences because without oxygen the potential for energy conservation and growth are limited compared to when oxygen is present. To test whether oxygen is present E. coli uses a protein called FNR, which acts as an oxygen sensor. It has a special co-factor called an iron-sulfur cluster that reacts with oxygen in a way that switches FNR off. This involves the conversion of the cluster from one form (called the [4Fe-4S] form) to another (called the [2Fe-2S] form). In the 'off-state' FNR is in its [2Fe-2S] form and cannot bind to DNA to activate expression of genes that are used during growth in the absence of oxygen. When there is no oxygen the iron-sulfur cluster remains in the [4Fe-4S] form and the protein can bind to DNA and activate expression of genes that are needed for growth in the absence of oxygen.For the last few years we have studied the reaction of oxygen with the FNR iron-sulfur cluster. These studies have revealed the complex biochemistry of the reaction and how this makes the FNR protein an exquisitely sensitive oxygen sensor. We recently showed that in its 'off-state' the [2Fe-2S] cluster is different from most other previously characterised [2Fe-2S] cluster cofactors and that this is a result of the fact that it is formed through oxidative conversion (which can be thought of as oxidative damage) of the [4Fe-4S] form. This results in an unusual modification of the protein in which sulfide from the initial [4Fe-4S] cluster is attached to the protein during the conversion reaction. This can be thought of as a form of stored sulfur and, remarkably, this can be used to repair the cluster back to its original [4Fe-4S] form when oxygen is no longer present. The unusual [2Fe-2S] cluster of FNR has also been discovered in other iron-sulfur cluster proteins, raising the possibility that repair of oxidatively damaged [4Fe-4S] clusters via this mechanism might be widespread.Using a wide range of approaches, we propose to investigate further the formation of the unusual [2Fe-2S] cluster and the repair of [4Fe-4S] cluster to determine the mechanism and the importance of this in vivo as a previously unrecognised pathway for repair of oxidatively damaged iron-sulfur clusters.

细菌几乎栖息在地球上的每一个环境小生境中，包括一些环境如此恶劣以至于许多其他形式的生命无法生存的环境。这一成功至少部分归功于细菌适应环境变化的能力，这种适应植根于它们响应外部和内部线索改变基因表达模式的能力。许多细菌监测的一个关键环境参数是氧浓度。我们特别感兴趣的是细菌大肠杆菌（E。大肠杆菌）。它的一个显着特性是，它能够在有氧和无氧的情况下茁壮成长。要做到这一点，它必须大大改变其新陈代谢，但这是有后果的，因为没有氧气，与氧气存在时相比，能量保存和生长的潜力是有限的。为了测试氧气是否存在E.大肠杆菌使用一种称为FNR的蛋白质，它充当氧传感器。它有一个特殊的辅因子，称为铁硫簇，它与氧气反应的方式关闭FNR。这涉及到簇从一种形式（称为[4Fe-4S]形式）到另一种形式（称为[2Fe-2S]形式）的转换。在“关闭状态”下，FNR处于其[2Fe-2S]形式，并且不能与DNA结合以激活在没有氧气的情况下生长期间使用的基因的表达。当没有氧气时，铁硫簇仍然以[4Fe-4S]形式存在，蛋白质可以与DNA结合，并激活在没有氧气的情况下生长所需的基因表达。在过去的几年里，我们研究了氧气与FNR铁硫簇的反应。这些研究揭示了反应的复杂生物化学，以及这如何使FNR蛋白成为一种非常敏感的氧传感器。我们最近表明，在其“关闭状态”的[2Fe-2S]簇是不同于大多数其他先前表征的[2Fe-2S]簇辅因子，这是一个事实，即它是通过氧化转化（可以被认为是氧化损伤）的[4Fe-4S]形式形成的结果。这导致蛋白质的不寻常的修饰，其中来自初始[4Fe-4S]簇的硫化物在转化反应期间附接到蛋白质。这可以被认为是储存硫的一种形式，并且值得注意的是，当氧气不再存在时，这可以用于将簇修复回其原始的[4Fe-4S]形式。在其他铁硫簇蛋白中也发现了FNR的不寻常的[2Fe-2S]簇，提高了通过这种机制修复氧化损伤的[4Fe-4S]簇的可能性。我们建议进一步研究不寻常的[2Fe-2S]团簇的形成和[4Fe-4S]的修复。集群，以确定机制和重要性，这在体内作为一个以前未被认可的途径修复氧化损伤的铁硫簇。

项目成果

期刊论文数量（10）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Differentiated, Promoter-specific Response of [4Fe-4S] NsrR DNA Binding to Reaction with Nitric Oxide.

DOI：
10.1074/jbc.m115.693192
发表时间：
2016-04-15
期刊：
The Journal of biological chemistry
影响因子：
0
作者：
Crack JC;Svistunenko DA;Munnoch J;Thomson AJ;Hutchings MI;Le Brun NE
通讯作者：
Le Brun NE

NsrR from Streptomyces coelicolor is a nitric oxide-sensing [4Fe-4S] cluster protein with a specialized regulatory function.

DOI：
10.1074/jbc.m115.643072
发表时间：
2015-05-15
期刊：
The Journal of biological chemistry
影响因子：
0
作者：
Crack JC;Munnoch J;Dodd EL;Knowles F;Al Bassam MM;Kamali S;Holland AA;Cramer SP;Hamilton CJ;Johnson MK;Thomson AJ;Hutchings MI;Le Brun NE
通讯作者：
Le Brun NE

The Di-Iron Protein YtfE Is a Nitric Oxide-Generating Nitrite Reductase Involved in the Management of Nitrosative Stress.

DOI：
10.1021/jacs.1c12407
发表时间：
2022-04-27
期刊：
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
影响因子：
15
作者：
Crack, Jason C.;Balasiny, Basema K.;Bennett, Sophie P.;Rolfe, Matthew D.;Froes, Afonso;MacMillan, Fraser;Green, Jeffrey;Cole, Jeffrey A.;Le Brun, Nick E.
通讯作者：
Le Brun, Nick E.

Biochemical properties of Paracoccus denitrificans FnrP: reactions with molecular oxygen and nitric oxide.