Deinococcus radiodurans is able to survive under extreme conditions, including high doses of ionizing radiation, desiccation and oxidative stress. In addition to enhanced DNA repair capabilities, an effective antioxidation system plays an important role in its robustness. Previous studies have linked the radiation resistance of D. radiodurans to its prolonged desiccation tolerance phenotype, which both cause DNA damage. In the current study, we investigated the roles of dr_1172 in D. radiodurans, the gene encoding a typical group 3 LEA protein (DrLEA3) conserved within Deinococcus species. In addition to the increased transcriptional level under oxidative stress, the inactivation of dr_1172-sensitized cells to H₂O₂ treatments and the reduced cellular antioxidation activities suggested that dr_1172 is involved in the cellular defense against oxidative stress. Moreover, DrLEA3 was enriched at the cell membrane and bound to various types of metal ions. Cells devoid of DrLEA3 showed a decreased intracellular Mn/Fe concentration ratio, indicating that DrLEA3 also plays a role in maintaining metal ion homeostasis in vivo.

辐射球菌能够在极端条件下生存，包括高剂量的电离辐射，干燥和氧化应激。除了增强的DNA修复能力外，有效的抗氧化系统在其坚固性方面也起着重要作用。先前的研究已将放射杜鹃的辐射抗性与其延长的耐干燥性表型联系起来，二者均引起DNA损伤。在当前的研究中，我们调查了dr_1172在D. radiodurans中的作用，D。radiodurans是编码Deinococcus物种中保守的典型3组LEA蛋白（DrLEA3）的基因。除了在氧化应激下增加转录水平外，dr_1172的失活对H ₂ O ₂处理敏感的细胞和降低的细胞抗氧化活性表明dr_1172参与了细胞对氧化应激的防御。此外，DrLEA3在细胞膜上富集并与各种类型的金属离子结合。不含DrLEA3的细胞显示出降低的细胞内Mn / Fe浓度比，这表明DrLEA3在体内也能维持金属离子稳态。