FIGURE 3.

Superimposition of MnmE and homology model of RbgA. A, an MnmE and RbgA homology model was superimposed using the LigAlign script in PyMOL, which aligned the two structures based on their ligand positions, which is GDP in this case. The K-loops of MnmE (green) and RbgA (brown) occupy a similar position (boxed) around the bound potassium in the crystal structure. B, an enlarged view of the catalytic pocket with GDP and bound potassium is shown in which Asn-130 from the P-loop of RbgA (brown) coordinates the bound K⁺ ion (indicated by a purple sphere) in a similar fashion as Asn-226 from the P-loop of MnmE (green) (indicated by arrows).