A tight tunable range for Ni(II) sensing and buffering in cells.
A tight tunable range for Ni(II) sensing and buffering in cells.
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DOI：
10.1038/nchembio.2310
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发表时间：
2017-04
影响因子：
14.8
通讯作者：
Robinson NJ
中科院分区：
文献类型：
--
作者：
Foster AW;Pernil R;Patterson CJ;Scott AJP;Pålsson LO;Pal R;Cummins I;Chivers PT;Pohl E;Robinson NJ
金属敏感转录调节因子的金属亲和力与细胞金属浓度共变超过12个数量级。为了理解这种关系的原因，我们确定了镍（II）-传感器InrS的结构，然后创建蓝藻（集胞藻PCC 6803），其中编码镍（II）-出口商和镍（II）-进口商的基因的转录由具有较弱镍（II）-亲和力的InrS变体控制。变异菌株是敏感的镍含量升高，并含有更多的镍，但增加是小相比，在镍（II）-亲和力的变化。所有的变体-传感器保留了在金属结合时抑制DNA结合的变构机制，但是仅当灵敏度被设置为在镍浓度的相对窄（小于2个数量级）范围内响应时才观察到对体内镍的响应。镍（II）-亲和力的InrS是调谐到细胞的金属浓度，而不是匡威。
The metal-affinities of metal-sensing transcriptional regulators co-vary with cellular metal concentrations over more than 12 orders of magnitude. To understand the cause of this relationship, we determined the structure of the Ni(II)-sensor InrS then created cyanobacteria (Synechocystis PCC 6803) in which transcription of genes encoding a Ni(II)-exporter and a Ni(II)-importer were controlled by InrS variants with weaker Ni(II)-affinities. Variant strains were sensitive to elevated nickel and contained more nickel but the increase was small compared to the change in Ni(II)-affinity. All of the variant-sensors retained the allosteric mechanism which inhibits DNA binding upon metal binding but a response to nickel in vivo was only observed when the sensitivity was set to respond within a relatively narrow (less than 2 orders of magnitude) range of nickel-concentrations. The Ni(II)-affinity of InrS is attuned to cellular metal concentrations rather than the converse.