PDF(Pubmed)
Abstract：
Deinococcus radiopugnans DY59 (formerly Deinococcus swuensis DY59) is a radiation-resistant bacterium isolated from soil. From the 3.5 Mb genomic DNA sequence of strain DY59 (December 2014), 31 insertion sequence (IS) elements of six IS families including IS1, IS4, IS5, IS66, IS630, and IS701 and five unclassified IS elements were detected. Upon induction of oxidative stress with 80 and 100 mM H2O2, the unique ISs of the IS4 family member were actively translocated into a carotenoid biosynthesis gene phytoene desaturase (QR90_10400), resulting in non-pigment phenotypic selection. Therefore, these active transpositions of a specific IS family member were induced by oxidative stress at 80 and 100 mM H2O2. Furthermore, D. radiopugnans DY59 exhibited extremely higher MIC values against H2O2 treatment. To explain this phenomenon, qRT-PCR was conducted to assess the expression levels of catalase and three LysR family regulators. Our findings indicated that the ISDrpg2 and ISDrpg3 elements of the IS4 family were actively transposed into the phytoene desaturase gene by H2O2 treatment via replicative transposition. However, high H2O2 resistance did not originate from H2O2-induced expression of catalase and LysR family regulators.
摘要：
放射异常球菌DY59（以前称为SwuensisDeinococusDY59）是一种从土壤中分离出的抗辐射细菌。从菌株DY59的3.5Mb基因组DNA序列（2014年12月），检测到包括IS1、IS4、IS5、IS66、IS630和IS701的6个IS家族的31个插入序列(IS)元件和5个未分类的IS元件。在用80和100mMH2O2诱导氧化应激后，IS4家族成员的独特ISs被主动转移到类胡萝卜素生物合成基因八氢烯去饱和酶（QR90_10400）中，导致非色素表型选择。因此,特定IS家族成员的这些活性转座是由80和100mMH2O2的氧化应激诱导的。此外，D.radiopugnansDY59对H2O2处理表现出极高的MIC值。为了解释这种现象，进行qRT-PCR以评估过氧化氢酶和三种LysR家族调节因子的表达水平。我们的发现表明，通过复制转座，通过H2O2处理，IS4家族的ISDrpg2和ISDrpg3元件被主动转座到植物烯去饱和酶基因中。然而,高H2O2抗性并非源于H2O2诱导的过氧化氢酶和LysR家族调节因子的表达。
