Response regulator (RR) is known a protein that mediates cell’s response to environmental changes. The effect of RR from extremophiles was still under investigation. In this study, response regulator homologs were mined from NGS data of Antarctic bacteria and overexpressed in Escherichia coli. Sixteen amino acid sequences were annotated corresponding to response regulators related to the two-component regulatory systems; of these, 3 amino acid sequences (DRH632, DRH1601 and DRH577) with high homology were selected. These genes were cloned in pRadGro and expressed in E. coli. The transformant strains were subjected to various abiotic stresses including oxidative, osmotic, thermal stress, and acidic stress. There was found that the robustness of E. coli to abiotic stress was increased in the presence of these response regulator homologs. Especially, recombinant E. coli overexpressing drh632 had the highest survival rate in oxidative, hypothermic, osmotic, and acidic conditions. Recombinant E. coli overexpressing drh1601 showed the highest tolerance level to osmotic stress. These results will be applicable for development of recombinant strains with high tolerance to abiotic stress.

中文翻译：

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通过表达来自南极细菌的推定应答调节同源物，提高了大肠杆菌对氧化应激的耐受性。

响应调节剂（RR）是一种介导细胞对环境变化的响应的蛋白质。极端微生物对RR的影响仍在研究中。在这项研究中，从南极细菌的NGS数据中提取了应答调节同源物，并在大肠杆菌中过表达。注释了对应于与两组分调节系统有关的应答调节剂的十六个氨基酸序列；其中，选择了3个具有高度同源性的氨基酸序列（DRH632，DRH1601和DRH577）。这些基因被克隆到pRadGro中并在大肠杆菌中表达。使转化株经受各种非生物胁迫，包括氧化胁迫，渗透胁迫，热胁迫和酸性胁迫。发现大肠杆菌的健壮性在这些反应调节因子同系物的存在下，非生物胁迫的耐受性增加。特别是，重组过表达的drh632大肠杆菌在氧化，低温，渗透和酸性条件下具有最高的存活率。重组过表达drh1601的大肠杆菌对渗透胁迫的耐受性最高。这些结果将可用于开发对非生物胁迫具有高度耐受性的重组菌株。