Metal dependence of CcLpxI. Panel A. Specific activity of CcLpxI in the presence of various divalent cations or EDTA. Three sets of assays were performed, each of which included a no additive (No add) control, as shown at the left. Each bar in the series of three bars represents a different concentration of each additive (e.g. 0.02, 0.2, or 2 mM). Standard assay conditions were used with enzyme at 10 nM. Panel B. The standard CcLpxI assay was used with 10 nM enzyme, but with increasing MgCl2 from 0 to 20 mM.