Identification of the Preferred DNA-Binding Sequence and Transcription Regulatory Network for the Thermophilic Zinc Uptake Regulator TTHA1292
Identification of the Preferred DNA-Binding Sequence and Transcription Regulatory Network for the Thermophilic Zinc Uptake Regulator TTHA1292
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DOI：
10.1128/jb.00303-22
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发表时间：
2022-10
影响因子：
3.2
通讯作者：
John K. Barrows;Alaina B. Westee;Arianna Y. Parrish;M. V. Van Dyke
中科院分区：
文献类型：
--
作者：
John K. Barrows;Alaina B. Westee;Arianna Y. Parrish;M. V. Van Dyke
发现生物体是如何感知和适应环境的，这对理解生物学至关重要。嗜热生物已经适应了在高温(>；50°C)下生存；然而，我们对这些生物如何适应环境变化的了解有限。摘要D-嵌段金属阳离子在大多数生物过程中是必不可少的；然而，过量的金属暴露对微生物的生存是有害的。为了严格控制重金属的调控，原核生物已经发展出几种机制来感知和适应细胞内和细胞外金属浓度的变化。铁摄取调节因子超家族转录因子与金属辅因子结合时与DNA结合，经常抑制金属转运相关基因的转录，从而对环境应激源产生基因组反应。尽管在中温生物中得到了广泛的研究，但描述嗜热菌中铁吸收调节剂同源物的信息很少。在这项研究中，我们对极端嗜热性嗜热菌HB8中的铁吸收调节同系物TTHA1292进行了生化特征研究。我们使用限制性内切酶、保护、选择和放大(REPSA)的组合方法确定了TTHA1292的首选DNA结合序列。我们将这个序列定位到Thermus thermophilus HB8基因组，并确定了TTHA1292转录调控网络，其中包括锌ABC转运子亚单位基因TTHA0596和TTHA0453/4。我们正式证明TTHA1292是锌吸收调节因子，并表明锌的配位对TTHA1292二聚体在体外DNA上的多聚体和体内转录抑制至关重要。发现生物体如何感知和适应环境对于理解生物学是至关重要的。嗜热生物已经适应了在高温(>；50°C)下生存；然而，我们对这些生物如何适应环境变化的了解有限。在这项研究中，我们在极端嗜热菌Thermus thermophilus HB8中发现了一个锌吸收调节因子，它提供了对锌可利用性波动的基因组反应。这些结果提供了对嗜热生物学以及锌摄取调节蛋白家族的深入了解。
Discovering how organisms sense and adapt to their environments is paramount to understanding biology. Thermophilic organisms have adapted to survive at elevated temperatures (>50°C); however, our understanding of how these organisms adapt to changes in their environment is limited. ABSTRACT D-block metal cations are essential for most biological processes; however, excessive metal exposure can be deleterious to the survival of microorganisms. To tightly control heavy metal regulation, prokaryotic organisms have developed several mechanisms to sense and adapt to changes in intracellular and extracellular metal concentrations. The ferric uptake regulator superfamily of transcription factors associates with DNA when complexed with a regulatory metal cofactor and often represses the transcription of genes involved in metal transport, thus providing a genomic response to an environmental stressor. Although extensively studied in mesothermic organisms, there is little information describing ferric uptake regulator homologs in thermophiles. In this study, we biochemically characterize the ferric uptake regulator homolog TTHA1292 in the extreme thermophile Thermus thermophilus HB8. We identify the preferred DNA-binding sequence of TTHA1292 using the combinatorial approach, restriction endonuclease, protection, selection, and amplification (REPSA). We map this sequence to the Thermus thermophilus HB8 genome and identify the TTHA1292 transcription regulatory network, which includes the zinc ABC transporter subunit genes TTHA0596 and TTHA0453/4. We formally implicate TTHA1292 as a zinc uptake regulator and show that zinc coordination is critical for the multimerization of TTHA1292 dimers on DNA in vitro and transcription repression in vivo. IMPORTANCE Discovering how organisms sense and adapt to their environments is paramount to understanding biology. Thermophilic organisms have adapted to survive at elevated temperatures (>50°C); however, our understanding of how these organisms adapt to changes in their environment is limited. In this study, we identify a zinc uptake regulator in the extreme thermophile Thermus thermophilus HB8 that provides a genomic response to fluctuations in zinc availability. These results provide insights into thermophile biology, as well as the zinc uptake regulator family of proteins.