Function
Antitoxin component of a type II toxin-antitoxin (TA) system. Plays a role in the speed with which bacteria traverse human epithelial cells; disruption of the locus increases the speed of trafficking about 2-4-fold. Binds to its own promoter, binding affinity of the FitAB complex is 20-30-fold higher than FitA alone. No nuclease activity was observed for the FitAB complex, perhaps because FitA (the antitoxin) prevents metal binding and thus catalysis by FitB.