Figure 3.

Occupancy of positive charges (viz., K⁺ ions and K196) and conformational dynamics of the products. (A) Occupancy of the W and the V sites (upper panel) by K⁺ ions (purple) and by the K196 side chain (yellow); and distances (lower panel) between the catalytic ions M_A–M_B (blue trace), and between the pro-Rp oxygen of the scissile phosphate and M_B (O_Rp–M_B, red trace) during MD at optimal concentrations. Normalized densities are on the right. (B-C) Same descriptors as in (A) for MD simulations at low [K⁺] (B) and at high [Mg²⁺] (C). At low [K⁺], the interaction between K196 and the scissile phosphate is more frequent (Figure 4B). At high [Mg²⁺], M_C approaches the scissile phosphate (green trace of M_C–P_SCI), while the M_A–M_B distance increases, preluding the release of the products (Figure 4C).