Fig. 7

Determination of intracellular cAMP levels. Bacterial cells were grown to an OD₆₀₀ of 0.7, disrupted and cAMP levels determined using the Cyclic Nucleotide XP Enzymatic Immunoassay kit. The amount of cAMP is given in nM representing a sample corresponding to 1 mg of total cellular protein. Bars indicate the standard deviation of three separate experiments. The cpdA::Tn transposon mutant has 12 mM of cAMP compared to the parent 17978hm strain which has 0.5 mM of cAMP within the cell. The cpdA::Tn(0249) mutant strain returned the cAMP levels to that of the 17978hm parent strain. The cpdA::Tn mutant strain harboring the empty vector pWH1266 had no effect on the cAMP levels. Asterisks indicate significant difference (p-value <0.001) as determined by one-way Anova