Figure 5 - full size

Figure 5.
Figure 5. View of octahedrally coordinated magnesium ions in BC crystal structures. Nucleotide molecules and protein residues are shown in sticks with the following atom colors: carbon, green; nitrogen, blue; oxygen, red; phosphorus, orange. Magnesium ions and water molecules are shown as green and red spheres. (A) View of two magnesium-binding sites in the SaBC/AMPPNP structure. (B) View of one magnesium-binding site in the PaBC/AMPCP structure.