Figure 2.

Activation of apo-LpxC by Zn²⁺ or Fe²⁺. Deacetylase activity as a function of either Zn²⁺ (closed circles) or Fe²⁺ (open circles) metal ion stoichiometry was measured for WT LpxC (A) and C63A LpxC (B). C63A LpxC activity was assayed with up to 50-fold excess Fe²⁺ (not shown). The deacetylase activity for the substrate myr-UDPGlcNAc (0.2 μM) was measured at 30 °C after incubation with varying equivalents of M²⁺, as described under “Materials and Methods”.