耐辐射异常球菌dlp基因缺失突变株构建及其生物学功能研究

Construction and Biological Characterization of Gene dlp Deletion Mutant of Deinococcus radiodurans R1

耐辐射异常球菌(Deinococcus radiodurans,DR)因其具有对非生物胁迫超强的抵抗能力而备受关注。旨在了解该菌亲水蛋白Dlp在细胞耐受非生物胁迫中的作用,采用融合PCR和基因同源重组技术,获得了dlp基因缺失突变株Δdlp,对野生型DR及突变株Δdlp进行非生物胁迫。结果表明,dlp的缺失导致DR细胞对高盐和氧化胁迫敏感。体外检测氧化胁迫条件下Dlp蛋白对苹果酸脱氢酶(MDH)和乳酸脱氢酶(LDH)活性的保护,结果显示,Dlp蛋白的加入能缓解氧化胁迫条件下MDH、LDH酶活性的损失。由此表明,亲水蛋白Dlp增强了耐辐射异常球菌对非生物胁迫的抗性,并能以类似分子伴侣的形式保护胁迫条件下酶的活性。

Deinococcu- radiodurans （ DR ） has drawn growing attentions for its superior resistance to abiotic stress. To investigate the effect of the hydrophilic protein Dip in cell tolerance to abiotic stress, the dlp deletion mutant strain （ Adlp ） was obtained by fusion PCR and homologous recombination in vivo. The assays of wild strain DR and mutant Adlp were analyzed under abiotic stress. The results showed that the deletion of dlp gene in D. radiodurans led cells to be more sensitive to high-salt and oxidative stresses. The in vitro protective effect of Dlp protein on the activities of MDH and LDH was measured under oxidative stress condition ; and the data demonstrated that the addition of Dlp protein alleviated the loss of activities of MDH and LDH under oxidative stressl Our findings indicated that hydrophilic protein Dip enhanced the resistanceofD, radioduranstoabioticstresses, and functioned as chaperone-like protein to protect enzyme aetivityunder abiotic stresses.