Fis also stimulates transcription of E. coli topA , when the bacteria experience oxidative-stress , something , although the severity of the oxidative-stress is unclear from an examination of the responses of classic oxidative-stress response genes .
Transcription of E. coli topA is driven by the interplay of at least four transcription start sites , allowing FIS to be both an activator of E. coli topA expression .
Thus , global supercoiling homeostasis is maintained in part by FIS 
Thus , global supercoiling homeostasis is maintained in part by FIS 
Thus , global supercoiling homeostasis is maintained in part by FIS 
Thus , global supercoiling homeostasis is maintained in part by FIS 
E. coli topA was upregulated in the absence of FIS in both exponential-growth and stationary-phase , whereas S. enterica topA expression was elevated in stationary-phase relative to wild-type cells .
E. coli topA was upregulated in the absence of FIS in both exponential-growth and stationary-phase , whereas S. enterica topA expression was unaffected in Dfis cells during exponential-growth .
Although topA promoter function has routinely been studied using plasmid-based systems , our results indicate that in E. coli the expression of plasmid-borne PtopAEc is enhanced by FIS whereas the chromosomal copy of the promoter is repressed by FIS -LRB- compare 4A -RRB- .
Although topA promoter function has routinely been studied using plasmid-based systems , our results indicate that in E. coli the expression of plasmid-borne PtopAEc is enhanced by FIS whereas the chromosomal copy of the promoter is repressed by FIS -LRB- compare Figs 3A -RRB- .