Figure 3.

(A) Time-dependent, thermal inactivation of CcrM. Reaction mixtures of 50 μl contained 250 nM CcrM incubated for variable time and initiated with the simultaneous addition of 5 μM N⁶23/30-mer and 50 μM AdoMet. Data were fit as previously described in Fig. 2. (B) Effect of increasing potassium acetate concentrations on CcrM activity. Reaction mixtures of 50 μl contained 250 nM CcrM preincubated with 5 μM N⁶45/50-mer and variable concentrations of potassium acetate before initiation by the addition of 50 μM AdoMet. The burst amplitudes and the observed rate constant for initial product formation are independent of varying salt concentration, whereas the steady-state rate decreases as the salt concentration is increased.