Deinococcus radiodurans YgjD and YeaZ are involved in the repair of DNA cross-links
Deinococcus radiodurans YgjD and YeaZ are involved in the repair of DNA cross-links
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DOI：
10.1007/s00792-012-0506-4
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发表时间：
2013-01-01
期刊：
影响因子：
2.9
通讯作者：
Narumi, Issay
中科院分区：
文献类型：
--
作者：
Onodera, Takefumi;Satoh, Katsuya;Narumi, Issay
大肠杆菌的同源基因ygjD和yeaZ在各种生物中高度保守。耐辐射细菌耐辐射球菌（Deinococcus radiodurans）基因组具有单一同源物ygjD （DR_0382）和yeaZ （DR_0756）。完全丢失一个或两个基因中的任何一个都不会导致细胞生长效率的显著变化，这表明两个基因对耐辐射菌的细胞活力都不是必需的，这与大肠杆菌、枯草芽孢杆菌和啤酒酵母等其他物种的情况不同。比较了过氧化氢（H2O2）、n -甲基-n′-硝基-n -亚硝基胍（MNNG）、紫外线（UV）、伽玛射线、顺铂和丝裂霉素C （MMC）对野生型菌株和耐辐射D. ygjD/yeaZ零突变体DNA损伤后的存活率。暴露于H2O2或MNNG后，零突变体的细胞活力没有降低。此外，与野生型菌株相比，零突变体暴露于伽马射线、紫外线辐射或顺铂后细胞活力的降低是微不足道的。有趣的是，零突变体对MMC表现出高度敏感性，MMC主要引起链间DNA交联。用表达这些基因的质粒转化后，零突变体对MMC的敏感性恢复到野生型的敏感性。这些结果提示耐辐射球菌ygjD和yeaZ基因参与DNA修复，并在DNA交联修复中发挥作用。
Orthologs of Escherichia coli ygjD and yeaZ genes are highly conserved in various organisms. The genome of the radioresistant bacterium Deinococcus radiodurans possesses single orthologs of ygjD (DR_0382) and yeaZ (DR_0756). Complete loss of either one or both genes did not result in any significant changes in cell growth efficiency, indicating that both genes are not essential for cell viability in D. radiodurans, unlike the case with other species such as E. coli, Bacillus subtilis and Saccharomyces cerevisiae. Survival rates following DNA damage induced by hydrogen peroxide (H2O2), N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), ultra violet (UV) radiation, gamma-rays, cisplatin and mitomycin C (MMC) were compared among the wild-type strain and D. radiodurans ygjD/yeaZ null mutants. Cell viability of the null mutants did not decrease following exposure to H2O2 or MNNG. In addition, the reduction in cell viability following exposure to gamma-rays, UV radiation or cisplatin was marginal in the null mutants compared to the wild-type strain. Interestingly, the null mutants exhibited high sensitivity to MMC, which mainly causes interstrand DNA cross-links. The sensitivity of the null mutants to MMC was restored to that of the wild type by transformation with plasmids expressing these genes. These results suggest that D. radiodurans ygjD and yeaZ genes are involved in DNA repair and play a role in the repair of DNA cross-links.