肠炎沙门菌延伸因子EF-Tu缺失株对环境压力的应答变化

Biological characteristics and stress response of EF-Tu defective mutant of Salmonella enterica

延伸热不稳定因子(EF-Tu)广泛存在于原核生物中,主要生物功能是在蛋白质合成过程中负责肽链的延伸。为研究肠炎沙门菌EF-Tu的tuf A基因缺失对环境压力的应答变化,本研究利用改进的Red同源重组方法构建肠炎沙门氏菌SM6株的tuf A缺失株,命名为SM6Δtuf A,并鉴定缺失株的形态学变化,分析耐酸性、渗透应力、温度缺氧应力、氧化应力的改变。结果表明缺失株对酸性条件及升温缺氧的耐受与亲本株相似;对渗透压的耐受稍强于亲本株,但差异不显著;对氧化压力的耐受显著弱于亲本株。本研究构建的肠炎沙门氏菌tuf A基因缺失株SM6Δtuf A,为进一步研究EF-Tu在沙门氏菌的生物学和致病机制中的作用奠定了基础。

The main biological function of elongation thermo unstable factor EF-Tu, widespread in prokaryotes, is responsible for extension peptide in protein synthesis. In order to investigate the stress response of tufA defective strain of Salmonella enterica, the tufA gene was knocked out from the chromosome of S.enterica SM6 strain using an improved Red homologous recombination system to construct the tufA delated S.enterica SM6 strain （SM6AtufA）. The results showed that the tolerance of SM6AtufA to acid, temperature and osmotic stress were similar to that of wild strain. However, the tolerance of SM6AtufA to oxidative stress was significantly higher. In conclusion, the constructed tufA defective mutant of S.enterica provided a basis for further study on the biological function and pathopoiesis of EF-Tu in Salmonella.