Figure 4: Perturbed metal geometry with altered activity in PA3825^EAL.

Idealised coordination geometries of the Mg²⁺- and Ca²-c-di-GMP PA3825^EAL complexes show the M1 metal ions coordinated in octahedral coordination. The M2 site metal in the Mg²⁺ -c-di-GMP PA3825^EAL complex is coordinated in an octahedral geometry, in comparison to the M2 metal site within the Ca²⁺ -c-di-GMP PA3825^EAL complex, which is coordinated in a trigonal bipyramidal geometry. Metal ions are shown as coloured transparent spheres (Mg²⁺ in magenta, Ca²⁺ in tan) with coordinating residues and nucleotide displayed in stick form with coordinating waters shown as red spheres.