Cloning and expression of luxS and pfs and in vitro biosynthesis autoinducer 2 of avian pathogenic Escherichia coli from Anhui Province
禽致病性大肠杆菌安徽分离株luxS和pfs基因的克隆、表达与细胞外合成AI-2 活性检测

Objective] The LuxS/AI-2 quorum sensing(QS) system shared by Gram-positive and Gram-negative bacteria involves the production of autoinducer-2(AI-2).In this study,the method of biosynthesis of AI-2 was established using recombinant LuxS and Pfs of avian pathogenic Escherichia coli(APEC),which will be benefit for future study of the role of AI-2 in APEC.Methods] We investigated AI-2 production in APEC by vibrio harveyi BB170(BB170).Furthermore,APEC LuxS and Pfs were expressed,purified and used to investigate the production of AI-2 in vitro.LuxS and Pfs were incubated with S-ribosylhomocysteine(SAH),the reaction was detected for the production of luminescence of BB170.Results] APEC can produce AI-2 by BB170 bioassay.Purified LuxS and Pfs enzymes incubated with SAH and produced 300μmol/L AI-2 in the reaction products.Conclusion] The results demonstrated that recombinant Pfs and LuxS synthesize AI-2 in vitro from SAH.These findings will be of benefit to future studies of the role of AI-2 in APEC.