Zambelli Barbara, Musiani Francesco, Ciurli Stefano
Department of Agro-Environmental Science and Technology, University of Bologna, Bologna, Italy.
Met Ions Life Sci. 2012;10:135-70. doi: 10.1007/978-94-007-2172-2_5.
The dramatic changes in the environmental conditions that organisms encountered during evolution and adaptation to life in specific niches, have influenced intracellular and extracellular metal ion contents and, as a consequence, the cellular ability to sense and utilize different metal ions. This metal-driven differentiation is reflected in the specific panels of metal-responsive transcriptional regulators found in different organisms, which finely tune the intracellular metal ion content and all metal-dependent processes. In order to understand the processes underlying this complex metal homeostasis network, the study of the molecular processes that determine the protein-metal ion recognition, as well as how this event is transduced into a transcriptional output, is necessary. This chapter describes how metal ion binding to specific proteins influences protein interaction with DNA and how this event can influence the fate of genetic expression, leading to specific transcriptional outputs. The features of representative metal-responsive transcriptional regulators, as well as the molecular basis of metal-protein and protein-DNA interactions, are discussed on the basis of the structural information available. An overview of the recent advances in the understanding of how these proteins choose specific metal ions among the intracellular metal ion pool, as well as how they allosterically respond to their effector binding, is given.
在进化过程中以及适应特定生态位的生活时，生物体所遇到的环境条件发生了巨大变化，这影响了细胞内和细胞外的金属离子含量，进而影响了细胞感知和利用不同金属离子的能力。这种由金属驱动的分化反映在不同生物体中发现的特定金属响应转录调节因子组中，这些调节因子精细地调节细胞内金属离子含量以及所有依赖金属的过程。为了理解这个复杂的金属稳态网络背后的过程，研究决定蛋白质 - 金属离子识别的分子过程，以及该事件如何转化为转录输出是必要的。本章描述了金属离子与特定蛋白质的结合如何影响蛋白质与DNA的相互作用，以及该事件如何影响基因表达的命运，从而导致特定的转录输出。基于现有的结构信息，讨论了代表性金属响应转录调节因子的特征，以及金属 - 蛋白质和蛋白质 - DNA相互作用的分子基础。概述了在理解这些蛋白质如何在细胞内金属离子池中选择特定金属离子，以及它们如何对效应物结合进行变构响应方面的最新进展。
