Screening New Regulator Of Salmonella

In previous studies we found that the PhoP/PhoQ two-component system and activated transcriptional regulation factor SlyA control the expression of several virulence factor genes (such as pagC) that are essential for bacterial virulence in Salmonella typhimurium in responding to environmental Mg2+. In order to explore new unknown transcription factors, we used EZ-Tn5 transposon to establish the Salmonella LT2 random mutation library. Based on this library we transformed pYS1000-pagC-up-lacZ plasmid into mutant strains and tested the β-galactosidase activity under low Mg2+ to measure pagC-up promoter transcriptional activity so as to find a gene that regulates pagC gene expression. Finally, we found a new regulatory factor that can regulate pagC gene expression and it is independent of the PhoP/ PhoQ system and SlyA. The result is fundamental for further research on new regulator and of great significance to explore gene expression regulation of prokaryote in depth.