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.

细菌几乎居住在地球上的每个环境利基市场，其中包括一些如此苛刻，以至于许多其他形式的生活无法生存。这种成功至少部分是由于细菌适应环境变化的能力，并且这种适应性植根于它们根据外部和内部提示改变基因表达模式的能力。许多细菌监测的关键环境参数是氧气浓度。我们对大肠杆菌（大肠杆菌）的细菌特别感兴趣。它的显着特性之一是，它能够在存在和不存在氧气的情况下繁衍生息。为此，它必须显着改变其新陈代谢，但这会带来后果，因为没有氧气，能量保护和生长的潜力与存在氧气相比受到限制。为了测试氧是否存在。它具有一个称为铁硫群集的特殊联合因素，该簇与氧气反应，以关闭FNR的方式。这涉及将群集从一种形式（称为[4fe-4s]形式）转换为另一种形式（称为[2FE-2S]形式）。在“州外”中，FNR处于其[2FE-2S]形式，无法与DNA结合以激活在没有氧气中生长过程中使用的基因的表达。当没有氧气时，铁硫簇仍留在[4FE-4S]形式中，并且该蛋白质可以与DNA结合并激活在没有氧气中生长所需的基因表达。在过去的几年中，我们研究了氧与FNR Iron-硫磺簇的反应。这些研究揭示了反应的复杂生物化学以及如何使FNR蛋白成为精心敏感的氧气传感器。我们最近表明，在其“偏离状态”中，[2FE-2S]簇不同于大多数先前表征的[2FE-2S]群集辅助因子，这是由于[4FE-4S]形式通过氧化转化（可以认为是氧化损害）形成的结果。这会导致蛋白质的异常修饰，其中在转化反应过程中，硫化物从初始[4FE-4S]簇附着在蛋白质上。可以将其视为一种储存的硫的形式，值得注意的是，当不再存在氧气时，可以用来将簇修复回到其原始的[4FE-4S]形式。在其他铁硫簇蛋白中也发现了不寻常的FNR [2FE-2S]簇，这增加了通过这种机制修复氧化损坏的[4FE-4S]簇的可能性，可能会广泛。该体内的重要性是修复氧化损坏的铁硫簇的先前未识别的途径。

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.