【目的】研究铜绿假单胞菌PAO1 PA2580基因的功能。【方法】构建了PA2580的敲除突变体及突变体互补体,通过最小抑制浓度测定、基因启动子活性检测、蛋白体外表达纯化等方法,对PA2580基因的功能进行了深入的研究。【结果】PA2580突变体对羧苄青霉素、氯霉素、环丙沙星的敏感性增强。PA2580基因的表达还受到不同种类的低于抑制浓度的抗生素的调节。PA2580蛋白产物以NADPH为电子供体,能够高效还原多种醌类物质。此外,PA2580突变体对过氧化氢敏感性增加,过氧化氢酶编码基因在PA2580突变体中的表达降低,表明PA2580与铜绿假单胞菌氧化压力耐受性相关。【结论】PA2580产物是NADPH-醌类的还原酶,其功能与铜绿假单胞菌对环境压力的耐受密切相关。
[ Objective] To investigate the function of gene PA2580 in Pseudomonas aeruginosa PAO1. [ Methods] We constructed a PA2580 knockout mutant of PAO1 and a complemented strain of the mutant. We studied the function of the gene PA2580 using both genetic and biochemical methods, including antibiotic minimum inhibition concentration (MIC) comparison, measurement of gene expression levels in different conditions, protein expression and purification in vitro and enzymatic activity detection. [ Results ] PA2580 mutant was more sensitive to carbenicillin, chloramphenicol and ciprofloxacin. PA2580 expression was regulated by sub-inhibitory concentrations of antibiotics. PA2580 protein reduced various quinones efficiently using NADPH as the electron donor. PA2580 mutant was more sensitive to hydrogen peroxide and the mutant showed decreased expression of catalase. These results indicate that PA2580 is involved in the tolerance of oxidative stress in P. aeruginosa. [ Conclusion ] The P. aeruginosa PA2580 protein physiologically functions as an NADPH quinone reductase which plays an important role in dealing with environment stress.