Biotechnology Research Division, Korea Atomic Energy Research Institute, Jeongeup 56212, Republic of Korea.
Aix Marseille Univ, CEA, CNRS, BIAM, Saint Paul-Lez-Durance, France.
FEMS Microbiol Rev. 2019 Jan 1;43(1):19-52. doi: 10.1093/femsre/fuy037.
Deinococcus bacteria are famous for their extreme resistance to ionising radiation and other DNA damage- and oxidative stress-generating agents. More than a hundred genes have been reported to contribute to resistance to radiation, desiccation and/or oxidative stress in Deinococcus radiodurans. These encode proteins involved in DNA repair, oxidative stress defence, regulation and proteins of yet unknown function or with an extracytoplasmic location. Here, we analysed the conservation of radiation resistance-associated proteins in other radiation-resistant Deinococcus species. Strikingly, homologues of dozens of these proteins are absent in one or more Deinococcus species. For example, only a few Deinococcus-specific proteins and radiation resistance-associated regulatory proteins are present in each Deinococcus, notably the metallopeptidase/repressor pair IrrE/DdrO that controls the radiation/desiccation response regulon. Inversely, some Deinococcus species possess proteins that D. radiodurans lacks, including DNA repair proteins consisting of novel domain combinations, translesion polymerases, additional metalloregulators, redox-sensitive regulator SoxR and manganese-containing catalase. Moreover, the comparisons improved the characterisation of several proteins regarding important conserved residues, cellular location and possible protein-protein interactions. This comprehensive analysis indicates not only conservation but also large diversity in the molecular mechanisms involved in radiation resistance even within the Deinococcus genus.
耐辐射球菌属的细菌以其对电离辐射和其他产生 DNA 损伤和氧化应激的物质的极端抗性而闻名。已有超过一百个基因被报道有助于耐辐射、干燥和/或氧化应激，这些基因编码参与 DNA 修复、氧化应激防御、调节以及功能未知或具有细胞外位置的蛋白质。在这里，我们分析了其他耐辐射的耐辐射球菌属物种中与辐射抗性相关的蛋白质的保守性。引人注目的是，这些蛋白质中的几十个在一种或多种耐辐射球菌属物种中缺失。例如，只有少数耐辐射球菌属特异性蛋白和与辐射抗性相关的调节蛋白存在于每个耐辐射球菌属中，特别是控制辐射/干燥响应调控子的金属肽酶/阻遏物对 IrrE/DdrO。相反，一些耐辐射球菌属物种拥有 D. radiodurans 缺乏的蛋白质，包括由新型结构域组合组成的 DNA 修复蛋白、跨损伤聚合酶、额外的金属调节剂、氧化还原敏感调节因子 SoxR 和含锰过氧化氢酶。此外，这些比较提高了几个蛋白质的特征，包括重要的保守残基、细胞位置和可能的蛋白质-蛋白质相互作用。这种全面的分析表明，即使在耐辐射球菌属内，涉及辐射抗性的分子机制不仅保守，而且具有很大的多样性。
