Bacterial gold sensing and resistance
Bacterial gold sensing and resistance
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DOI：
10.1007/s10534-010-9393-2
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发表时间：
2011-06
期刊：
影响因子：
3.5
通讯作者：
S. K. Checa;F. C. Soncini
中科院分区：
文献类型：
--
作者：
S. K. Checa;F. C. Soncini
金离子通过环境被动员和散布，并通过非特异性摄入进入细胞。为了避免即使在非常低的浓度下也会发生的有害作用，细菌如沙门氏菌（Salmonella enterica）和耐金属贪铜菌（Cupriavidus metallidurans）使用Au特异性MerR型转录调节子来检测这些有毒离子的存在，并控制特异性抗性因子的表达。与相关的铜传感器CueR相反，Au选择性金属调节蛋白能够区分Au（I）与Cu（I）或Ag（I）。这是通过精细调节单一二硫代金属与蛋白质的金属结合位点处的保守半胱氨酸残基的配位来实现的，以与Cu传感器相比降低对Cu（I）的亲和力，同时保持或甚至增加对Au（I）的亲和力。在沙门氏菌中，戈尔斯不仅使Au（I）优先于Cu（I）或Ag（I）结合，而且在其调节的启动子中区分其靶识别位点，从而最小化CueR控制的操纵子的交叉激活。在这个意义上说，一个选择性的Au感官设计的存在将允许物种窝藏居民铜稳态系统，以消除有毒离子，而不影响铜收购在Au丰富的环境。
Gold ions are mobilized and disseminated through the environment and enter into the cells by non-specific intake. To avoid deleterious effect that occurs even at very low concentrations, bacteria such asSalmonella entericaandCupriavidus metalliduransuse Au-specific MerR-type transcriptional regulators to detect the presence of these toxic ions, and control the expression of specific resistance factors. In contrast to the related copper sensor CueR, the Au-selective metalloregulatory proteins are able to distinguish Au(I) from Cu(I) or Ag(I). This is achieved by finely tuning a single dithiolate metal coordination with conserved cysteine residues at the metal binding site of the proteins to lower the affinity for Cu(I) in comparison to the Cu-sensors, while maintaining or even increasing the affinity for Au(I). InSalmonella, GolS not only privileges the binding of Au(I) over Cu(I) or Ag(I), but also distinguishes its target recognition sites in its regulated promoters minimizing cross-activation of CueR-controlled operators. In this sense, the presence of a selective Au sensory devise would allow species harbouring resident Cu-homeostasis systems to eliminate the toxic ion without affecting Cu acquisition in Au rich environments.