The discernment of metals by a set of DNA-binding transcriptional regulators

通过一组 DNA 结合转录调节因子来识别金属

基本信息

批准号：
BB/H006052/2
负责人：
Nigel Robinson
金额：
$ 36.73万
依托单位：
Durham University
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2011
资助国家：
英国
起止时间：
2011 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=BB%2FH006052%2F2
关键词：
discernment metals set DNA binding

项目摘要

It has recently been estimated that 47% of all enzymes require metals such as copper, zinc, nickel, cobalt, iron, manganese, calcium and magnesium. On average, almost half of all attempts to manipulate the activities of cells (for example in metabolic engineering) will involve an enzyme which must somehow acquire the correct metal. Selection of the correct metals by enzymes is substantially governed by metal-availability at the site of protein folding, and metal-availability in cells is, in turn, substantially governed by sensors that detect excess or deficiency of each metal. Crucially, these sensors somehow discern the different inorganic elements, one from another. A zinc-sensor called MTF1 is currently the only DNA-binding, metal-binding, metal-sensor known in humans. However, over the last two decades we, and many others, have discovered an expanding repertoire of bacterial DNA-binding metal-sensing proteins. These sensors turn genes on or off; each sensor acting in response to specific metals. The genes that some of the sensors regulate have been found and the metals they respond to identified. Among the regulated genes are ones encoding importers that acquire more of those metals which are needed and exporters that pump out metals that are surplus to requirements and/or solely toxic. The sensors work in several different ways. Some bind to DNA and, in effect, switch a gene off. When the sensor binds to the metal its structure changes such that it no longer binds tightly to the DNA and the gene becomes active. Other metal-sensors do the reverse. Their structure changes upon binding a metal such that only under these conditions do they bind tightly to DNA and switch a gene off. Finally, some sensors bind to DNA both with and without a metal but a change in protein structure caused by binding the metal distorts the DNA to activate gene expression. The characterisation of these assorted metal sensors has provided an opportunity to explore how metals are discerned. A naïve expectation was that each sensor would tightly bind the metal it detected and bind all other metals weakly or not at all. But this turns out not to be the case and indeed fundamental rules of bioinorganic chemistry imply that for flexible proteins it could rarely be the case. Thus the question becomes, regardless of the mechanism of gene regulation, how does each metal trigger the correct sensor protein? To answer this question we need to consider a set of sensors from a single bacterium. We need to consider their affinities for different metals, not in isolation, but in the context of the metal-affinities of all of the other metal-sensors in the same cell. A simple explanation could be that the sensors give the correct integrated response as a function of their 'relative' metal affinities rather than their 'absolute' metal affinities: the cobalt sensor being the tightest cobalt-binder of the set, the zinc-sensor being the tightest zinc-binder of the set, and so on. The organism chosen for this work, a cyanobacterium, has a set of metal-sensors with properties that are peculiarly well suited to comparing their metal-affinities, one against the other, using a method that we exploited and published in 2007. In this program we will also characterize at least one new metal-sensor. This is fundamental research. Discerning metals is, literally, elemental to life. Nonetheless, it has implications and applications across the biosciences and biotechnology and for this reason we, and the rest of the 'Metals in Cells' group at Newcastle, actively collaborate with the biotechnology industrial sector. Industrial links related to this programme are described in the impact plan.

最近估计，所有酶中有47％需要金属，例如铜，锌，镍，钴，铁，锰，钙和镁。平均而言，几乎所有操纵细胞活性的尝试（例如，代谢工程）将涉及一种酶，该酶必须以某种方式获得正确的金属。酶在蛋白质折叠部位的金属可用性基本上控制了正确的金属，并且细胞中的金属可用性基本上由检测到每种金属的超过或缺乏的传感器控制。至关重要的是，这些传感器以某种方式辨别出不同的无机元素，一个元素。一个称为MTF1的锌传感器是目前唯一的DNA结合，金属结合，金属传感器。但是，在过去的二十年中，我们和许多其他人发现了细菌DNA结合金属感应蛋白的扩展曲目。这些传感器打开或关闭基因；每个传感器响应特定金属的作用。已经发现了某些传感器的基因以及它们响应的金属。在受管制的基因中，有一个编码进口商的基因，这些进口商会获取更多所需的金属，以及将盈余金属泵出来的出口商，这些金属会剩余到需求和/或完全有毒。传感器以几种不同的方式工作。有些人与DNA结合，实际上是关闭基因。当传感器与金属结合时，其结构会变化，使其不再与DNA紧密结合，并且基因变得活跃。其他金属传感器会相反。它们的结构在结合金属后会发生变化，使得它们只有在这些条件下才能与DNA紧密结合并关闭基因。最后，某些传感器在有或没有金属的情况下与DNA结合，但通过结合金属引起的蛋白质结构的变化会使DNA扭曲DNA激活基因表达。这些各种金属传感器的表征为探索金属的识别提供了机会。一个天真的期望是，每个传感器都会紧密地绑定其检测到的金属，并薄弱或根本没有将所有其他金属绑定。但事实证明，生物无机化学的基本规则实际上并非如此，这暗示着柔性蛋白很少是这种情况。无论基因调节的机制如何，每个金属如何触发正确的传感器蛋白？要回答这个问题，我们需要考虑来自单个细菌的一组传感器。我们需要考虑它们对不同金属的亲和力，而不是孤立的，而是在同一细胞中所有其他金属传感器的金属损失的背景下。一个简单的解释可能是，传感器给出了正确的集成响应，这是其“相对”金属亲和力的函数，而不是其“绝对”金属亲和力：钴传感器是元组中最紧的钴 - 碳传感器，锌传感器是套件最紧密的锌 - 固定锌 - 元素，等等。为这项工作选择的有机体，一种蓝细菌，具有一组具有特性的金属传感器，这些特性非常适合比较其金属属性，一种是使用我们在2007年探索和发布的方法。在此程序中，我们还将至少表征一个新的金属传感器。这是基本研究。从字面上看，辨别金属是生命的基础。尽管如此，它在生物科学和生物技术方面具有含义和应用，因此，我们以及纽卡斯尔的其他“细胞金属”组的其余部分与生物技术工业部门积极合作。影响计划中描述了与该计划相关的工业链接。

项目成果

期刊论文数量（6）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Co(ll)-detection does not follow Kco(ll) gradient: channelling in Co(ll)-sensing.

Co(II)-检测不遵循Kco(II)梯度：Co(II)-传感中的通道。

DOI：
10.1039/c3mt20241k
发表时间：
2013
期刊：
integrated biometal science
影响因子：
0
作者：
Patterson CJ
通讯作者：
Patterson CJ

Metal specificity of cyanobacterial nickel-responsive repressor InrS: cells maintain zinc and copper below the detection threshold for InrS.

DOI：
10.1111/mmi.12594
发表时间：
2014-05
期刊：
Molecular microbiology
影响因子：
3.6
作者：
Foster AW;Pernil R;Patterson CJ;Robinson NJ
通讯作者：
Robinson NJ

A tight tunable range for Ni(II) sensing and buffering in cells.

DOI：
10.1038/nchembio.2310
发表时间：
2017-04
期刊：
Nature chemical biology
影响因子：
14.8
作者：
Foster AW;Pernil R;Patterson CJ;Scott AJP;Pålsson LO;Pal R;Cummins I;Chivers PT;Pohl E;Robinson NJ
通讯作者：
Robinson NJ

Promiscuity and preferences of metallothioneins: the cell rules.