Identification of the Clostridium perfringens genes involved in the adaptive response to oxidative stress
Identification of the Clostridium perfringens genes involved in the adaptive response to oxidative stress
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DOI：
10.1128/jb.184.9.2333-2343.2002
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发表时间：
2002-05-01
影响因子：
3.2
通讯作者：
Reysset, G
中科院分区：
文献类型：
--
作者：
Briolat, V;Reysset, G
产气荚膜梭菌是一种普遍存在于空气、土壤、动物和人类中的革兰氏阳性病原体。虽然产气荚膜梭菌是严格厌氧的，但营养细胞和静止细胞可以在氧和/或低浓度的超氧化物和羟基自由基的存在下在生长停滞阶段存活。事实上，它具有对氧化应激的适应性反应，可以在有氧和无氧条件下被激活。为了鉴定参与这种氧化应激反应的基因，通过Tn 916插入诱变产生产气荚膜梭菌菌株13突变体，并筛选对各种氧化应激的抗性或敏感性。12个敏感的突变体中有3个在同一操纵子中独立插入了一个单拷贝的转座子，作为枯草芽孢杆菌编码NADPH脱氢酶的ydaD和ycdF基因的两个基因。互补实验和敲除实验表明，这两个基因都是C.产气荚膜梭菌是产气荚膜梭菌的主要致病菌，并且可能负责NADPH的产生，NADPH是维持生长停滞细胞中细胞内氧化还原平衡所需的。其他Tn 916破坏的基因也被证明在氧化应激反应中发挥重要作用。这是第一次，其中一些基因（例如，编码ATP依赖性RNA解旋酶的基因、β-葡糖醛酸糖苷酶基因和编码非典型铁硫prismane蛋白的基因）已经显示参与氧化反应。
Clostridium perfringens is a ubiquitous gram-positive pathogen that is present in the air, soil, animals, and humans. Although C perfringens is strictly anaerobic, vegetative and stationary cells can survive in a growth-arrested stage in the presence of oxygen and/or low concentrations of superoxide and hydroxyl radicals. Indeed, it possesses an adaptive response to oxidative stress, which can be activated in both aerobic and anaerobic conditions. To identify the genes involved in this oxidative stress response, C perfiingens strain 13 mutants were generated by Tn916 insertional mutagenesis and screened for resistance or sensitivity to various oxidative stresses. Three of the 12 sensitive mutants examined harbored an independently inserted single copy of the transposon in the same operon as two genes orthologous to the ydaD and ycdF genes of Bacillus subtilis, which encode a putative NADPH dehydrogenase. Complementation experiments and knockout experiments demonstrated that these genes are both required for efficient resistance to oxidative stress in C. perfringens and are probably responsible for the production of NADPH, which is required for maintenance of the intracellular redox balance in growth-arrested cells. Other Tn916 disrupted genes were also shown to play important roles in the oxidative stress response. This is the first time that some of these genes (e.g., a gene encoding an ATP-dependent RNA helicase, the beta-glucuronidase gene, and the gene encoding the atypical iron sulfur prismane protein) have been shown to be involved in the oxidative response.