Shubnikov Institute of Crystallography of Federal Scientific Research Centre "Crystallography and Photonics", Russian Academy of Sciences, Leninskiy Prospect, 59, 119333 Moscow, Russia.
National Research Center "Kurchatov Institute", Akademika Kurchatova pl., 1, 123182 Moscow, Russia.
Int J Mol Sci. 2023 May 10;24(10):8534. doi: 10.3390/ijms24108534.
In response to adverse environmental factors, cells actively produce Dps proteins which form ordered complexes (biocrystals) with bacterial DNA to protect the genome. The effect of biocrystallization has been described extensively in the scientific literature; furthermore, to date, the structure of the Dps-DNA complex has been established in detail in vitro using plasmid DNA. In the present work, for the first time, Dps complexes with genomic DNA were studied in vitro using cryo-electron tomography. We demonstrate that genomic DNA forms one-dimensional crystals or filament-like assemblies which transform into weakly ordered complexes with triclinic unit cells, similar to what is observed for plasmid DNA. Changing such environmental factors as pH and KCl and MgCl concentrations leads to the formation of cylindrical structures.
针对不利的环境因素，细胞会积极产生 Dps 蛋白，这些蛋白与细菌 DNA 形成有序的复合物（生物晶体），以保护基因组。生物晶体形成的效果在科学文献中有广泛的描述；此外，迄今为止，已经使用质粒 DNA在体外详细建立了 Dps-DNA 复合物的结构。在本工作中，首次使用 cryo-electron tomography 体外研究了与基因组 DNA 的 Dps 复合物。我们证明了基因组 DNA 形成一维晶体或丝状组装体，这些组装体转化为具有三斜单位细胞的弱有序复合物，类似于质粒 DNA 中观察到的情况。改变 pH 值和 KCl 和 MgCl 浓度等环境因素会导致形成圆柱形结构。
