FIGURE 2.

Specific activity of phosphodiesterases toward c-di-AMP. Phosphodiesterases (MPN140, MPN549, GdpP: 100 nM, in addition 50 and 10 nM for MPN549) were added to 100 μM c-di-AMP in 100 mM Tris-HCl pH8.3, 10 mM NaCl, 0.1 mM MnCl₂ at 37°C. Reactions were stopped at 0, 5, 10, 15, 30, 60, 120, and 240 min. Upon addition of KBr and coralyne and excitation at 420 nm, fluorescence at 475 nm was measured. The ratio of c-di-AMP-mediated emission vs. a standard without c-di-AMP is shown. Results from a typical experiment are shown. The replicates showed similar results.