Figure 4.

Complex initiated trans-cleavage reactions in various cations. Complex initiated cleavage assays were conducted as described previously (16), utilizing glmS-Rz-S construct, at pH 7.5. Experiments were carried out over a range of cation concentrations using saturating amounts of GlcN6P. Reaction rates were plotted as a function of cation concentration on a log scale. The symbols used for each cation are shown in the graph as follows, Mg²⁺ filled circles, Ca²⁺ open circles, Mn²⁺ filled squares, Co(NH₃)₆³⁺ open squares, Na⁺ filled diamonds. All data points are the average of three replicate experiments with error bars set at one standard deviation from the mean. Individual titrations were fit to the Hill equation as described in the Experimental Procedures. k_obs^max, K_d^app and the Hill cofficient, n, for each cation are reported in Table 1.