Figure 12.

In our Model 1 (M1),⁵⁸ the two water molecules HOH604 and HOH608 are within the DNC as observed in the X-ray crystal structure 3S8G.¹⁴ The size of our DNC model clusters are the same as state A shown in Figure 7. A clearer view of the top portion of the cluster (top M1) and the central portions of states P_R and F are given here. In Model 2 (M2), the two water molecules HOH604 and HOH608 are shifted to the upper part of the DNC to the positions as shown on the upper-right (top M2) for protonated His376-H⁺ and lower-right (top M2) for neutral His376 cases.⁵⁸