FIG. 4.

The recognition of AMP and AMPCPR. (A) The recognition site in the product complex of Ndx2 with Mg²⁺ and AMP. Mg²⁺ ions are shown as magenta spheres. AMP is shown as white lines. (B) The recognition site in the substrate analog complex with Mg²⁺ and AMPCPR. Mg²⁺ is shown as magenta spheres. AMPCPR is shown as white lines. (C) Recognition of ADPR by Ndx4. The binding residues are conserved among ADPRase-I enzymes. Gd³⁺ ions are shown as magenta spheres. ADPR is shown as white lines. (D) Recognition of adenosine by EcORF186. Adenosine is shown as white lines. Residue numbers followed by asterisks indicate residues of the other subunit in the dimer.