A 'through-DNA' mechanism for metal uptake-vs.-efflux regulation.
A 'through-DNA' mechanism for metal uptake-vs.-efflux regulation.
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金属摄取与流出调节的“通过 DNA”机制。
DOI：
10.1101/2023.12.05.570191
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Chen,Peng
中科院分区：
文献类型：
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作者：
Chakraborty,UditKumar;Park,Youngchan;Sengupta,Kushal;Jung,Won;Joshi,ChandraP;Francis,DanielleH;Chen,Peng
像锌这样的过渡金属对包括细菌在内的所有生物体都是必不可少的，但它们在细胞中的浓度波动可能是致命的。生物体因此进化出复杂的细胞金属稳态机制。一种机制范式涉及成对的转录调节子感测细胞内金属浓度以调节金属摄取和流出。在这里，我们报告，Zur和ZntR，一个典型的对锌吸收和流出的监管机构在E。大肠杆菌，分别可以通过DNA协调它们的调节，除了传感细胞Zn 2+浓度。使用活细胞单分子跟踪andin vitro单分子FRET测量的组合，我们表明，unmetallated ZntR可以提高解结合动力学的Zur从DNA直接作用于DNA复合物，可能通过形成异聚三元和四元复合物，涉及蛋白质-DNA和蛋白质-蛋白质相互作用。当细菌遇到不断变化的锌环境时，这种“通过DNA”机制可能在功能上促进锌吸收调节的切换;它也可能与调节锌吸收-相对于锌吸收-各种金属在不同细菌物种和酵母中的流出。
Transition metals like Zn are essential for all organisms including bacteria, but fluctuations of their concentrations in the cell can be lethal. Organisms have thus evolved complex mechanisms for cellular metal homeostasis. One mechanistic paradigm involves pairs of transcription regulators sensing intracellular metal concentrations to regulate metal uptake and efflux. Here we report that Zur and ZntR, a prototypical pair of regulators for Zn uptake and efflux inE. coli, respectively, can coordinate their regulation through DNA, besides sensing cellular Zn2+concentrations. Using a combination of live-cell single-molecule tracking andin vitrosingle-molecule FRET measurements, we show that unmetallated ZntR can enhance the unbinding kinetics of Zur from DNA by directly acting on Zur-DNA complexes, possibly through forming heteromeric ternary and quaternary complexes that involve both protein-DNA and protein-protein interactions. This ‘through-DNA’ mechanism may functionally facilitate the switching in Zn uptake regulation when bacteria encounter changing Zn environments; it could also be relevant for regulating the uptake-vs.-efflux of various metals across different bacterial species and yeast.