Division of Ecological Safety, National Institute of Ecology, Seocheon, Republic of Korea.
Division of Ecological Safety, National Institute of Ecology, Seocheon, Republic of Korea.
Biochem Biophys Res Commun. 2023 Jul 30;667:180-185. doi: 10.1016/j.bbrc.2023.05.064. Epub 2023 May 18.
The DNA-binding protein from starved cells, known as DPS, has been characterized as a crucial factor in protecting E. coli from external stresses. The DPS functions in various cellular processes, including protein-DNA binding, ferroxidase activity, compaction of chromosome and regulation of stress resistance gene expression. DPS proteins exist as oligomeric complexes; however, the specific biochemical activity of oligomeric DPS in conferring heat shock tolerance has not been fully understood. Therefore, we investigated the novel functional role of DPS under heat shock. To elucidate the functional role of DPS under heat shock conditions, we purified recombinant GST-DPS protein and demonstrated its thermostability and existence in its highly oligomeric form. Furthermore, we discovered that the hydrophobic region of GST-DPS influenced the formation of oligomers, which exhibited molecular chaperone activity, thereby preventing the aggregation of substrate proteins. Collectively, our findings highlight the novel functional role of DPS, as a molecular chaperone and may confer thermotolerance to E. coli.
饥饿细胞中的 DNA 结合蛋白,称为 DPS,已被确定为保护大肠杆菌免受外部压力的关键因素。DPS 在多种细胞过程中发挥作用,包括蛋白-DNA 结合、铁氧还酶活性、染色体紧缩和调节应激抗性基因表达。DPS 蛋白以寡聚体复合物的形式存在;然而,寡聚态 DPS 在赋予耐热性方面的具体生化活性尚未完全理解。因此,我们研究了 DPS 在热激下的新功能作用。为了阐明热激条件下 DPS 的功能作用,我们纯化了重组 GST-DPS 蛋白,并证明了其热稳定性和高度寡聚形式的存在。此外,我们发现 GST-DPS 的疏水区影响寡聚体的形成,寡聚体表现出分子伴侣活性,从而防止底物蛋白的聚集。总的来说,我们的发现强调了 DPS 作为分子伴侣的新功能作用,并可能赋予大肠杆菌耐热性。