FIG. 2.
Repression of SPI2 expression correlates with chelator-metal ion complex stability. Salmonella containing an ssaG-gfp fusion was grown for 4 h in M9 glucose minimal medium (SPI2 repressing conditions), and this was followed by 4 h of treatment with 10 mM CDTA in the presence of different concentrations of metal salts. Log Ka values are indicated beneath the metals on the x axis. We found that the anion did not appear to have an effect on ssaG expression [chloride versus sulfate for Mg(II) and Mn(II)].