Chang Shenghe, Shu Haiyan, Lu Huiming, Hua Yuejin, Li Zongwei, Tian Shuangqi, Wang Yanping, Chen Linhai, Tan Zhongfang, Qin Guangyong
Ion Beam Bio-engineering Lab, School of Physics, Zhengzhou University, Zhengzhou 450052, China.
Wei Sheng Wu Xue Bao. 2008 Jan;48(1):57-62.
Deinococcus radiodurans R1 has extraordinary resistance to radiation. DRB0099 might play an important role in protecting the bacterium against radiation. To verify the inference, we deleted drb0099 and constructed the mutant. Comparing with the wild type, the mutant grew more slowly in the beginning cultivation stage (0-16 h) under normal conditions. After being cultivated for 16 h, the mutant grew faster than the wild type. The biomass concentration of the wild type was always higher than that of the mutant. The mutant cell's fission during the growing phase might be blocked. When treated with UV, although Deinococcus radiodurans R1 cultures' survival fraction was lower with UV treatment time increased, the survival fraction was much higher than that of drb0099. The wild type could repair DNA double strands breaks better than the mutant. The gene drb0099 might directly relate with the DNA repair system. The mutant was more sensitive to H202 than the wild type. The wild type could better protect protein and DNA against reactive oxygen species (ROS) or in DNA repair. When treated with low concentration of H2O2, although the survival fraction of both R1 and the mutant decreased, the difference was small. However, with the concentration of H2O2 increased, the difference value increased. The mutant without drb0099 was more easily injured than the wild type with ROS increased. Under UV or H2O2 treatment, DRB0099 could protect protein and DNA from oxidation.
耐辐射球菌R1对辐射具有非凡的抗性。DRB0099可能在保护该细菌免受辐射方面发挥重要作用。为了验证这一推断，我们删除了drb0099并构建了突变体。与野生型相比，突变体在正常条件下的初始培养阶段（0 - 16小时）生长较慢。培养16小时后，突变体的生长速度比野生型快。野生型的生物量浓度始终高于突变体。突变体细胞在生长阶段的分裂可能受阻。用紫外线处理时，尽管随着紫外线处理时间的增加，耐辐射球菌R1培养物的存活分数降低，但存活分数远高于drb0099突变体。野生型比突变体更能有效地修复DNA双链断裂。基因drb0099可能与DNA修复系统直接相关。突变体比野生型对H2O2更敏感。野生型在保护蛋白质和DNA免受活性氧（ROS）损伤或进行DNA修复方面表现更好。用低浓度的H2O2处理时，尽管R1和突变体的存活分数均下降，但差异较小。然而，随着H2O2浓度的增加，差异值增大。缺失drb0099的突变体比野生型更容易受到ROS增加的损伤。在紫外线或H2O2处理下，DRB0099可以保护蛋白质和DNA免受氧化。
