FIGURE 5.

Kinetics of RelH_Cg (A) and Rel_Cg (B) using pGpp, ppGpp and pppGpp as substrates. Specific activities were determined for different substrate concentrations by in vitro analysis and given in kat per mol of the respective enzyme. The reaction mixtures contained 50 mM HEPES-Na (pH 8.0), 200 mM NaCl, 1 mM MnCl₂ as well as 52.3 nM RelH_Cg or 98.2 nM Rel_Cg, respectively. The incubation times of the different enzyme-substrate combinations were adapted to the values determined in preliminary tests and ranged from 20 to 45 min. The incubation temperature was 30°C. Mean values and standard deviations shown were calculated from three replicates.