Fig. 5.

Evolution of average distances of ligands coordinating the catalytic and nucleotide-binding Mg²⁺ ions along the reaction coordinate. For atom types, see Fig. 2. States 1–7 correspond to Fig. 4. The extent of thumb closing (χ₁ in Upper), and a crucial distance for the chemical reaction (O3′ of last primer residue to P^α of dCTP in Lower) are also provided.