Fig. 1.

Endo IV structure and schematic mechanism. (a) QM/MM model of endo IV: the QM subsystem is in ball-and-stick representation and highlighted by a red circle; the enzyme and DNA substrate are in cartoon representation (color-coded according to secondary structure) along with a van der Waals surface for the protein atoms. A cut-plane through the protein was used to reveal the trinuclear active site. (b) Schematic representation of the mechanism. Zinc coordination distances for the reactant (R), transition state (TS; ξ = 0) and product (P) are included in supporting information (SI) Table 1.