Figure 5.

Superposition of active sites for the calculated transition states (TS1 top, TS2 bottom). Mg²⁺ structures are shown in orange and Mn²⁺ structures are shown in purple. Hydrogen atoms except for the transferred proton have been omitted for clarity. The metals, O3′, Pα, waters that complete the metal coordination and transferred proton are highlighted as spheres. Catalytic metal is on the left and nucleotide binding metal is on the right. Metal ligand distances are reported in table S1 (supplementary materials).