颗粒裂解肽G13结构域引发细菌SOS反应

G13 domain of granulysin induces the SOS response in bacteria

目的利用自发光lux基因作为报告基因,检测颗粒裂解肽G13结构域对SOS启动子控制下的报告基因表达的影响。方法 pBAD-G13工程菌和鼠伤寒沙门菌Sal94混合培养,选取特定时间点测量混合菌液的光吸收值和A600值,通过公式运算,计算其单位细菌产生的平均光吸收值。结果重组G13结构域可诱导报告基因的表达,且诱导表达的水平具时间效应,呈现峰型图,在处理的开始阶段(4min左右)lux基因被强烈诱导表达并且达到峰值,随后lux基因表达水平逐渐平缓下降。结论重组G13结构域引起细菌内SOS操纵子阻遏蛋白LexA蛋白的降解,诱导发生SOS反应。

Objective By using self-luminous lux gene as a reporter gene we detected the effects of G13 domain of granulysin on the expression of the reporter gene under the control of the SOS promoter. Methods We got pBAD-G13 engineering bacteria and Salmonella typhimurium Sa194 mixed culture, and selected a specific time to measure RLU and A600 values. We calculated RLU of the units of bacteria according to the formula. Results We showed that recombinant G 13 domain did induce the expression of the reporter gene, and the expression level was time-dependent and took on the form of a peak curve. At about 4 min of induction, the expression level of the reporter gene reached its peak, and then gradually decreased. Conclusions The recombinant G 13 domain triggered the degradation of the repressor protein LexA, and induced SOS response in the bacterial cells.