SidE ADP binding.
A, structural similarity of the SidE domain of lpg1496 (yellow) and LmjPDEB1 (PDB code 2R8Q, purple). B, superposition of the active site of LmjPDEB1 (purple) and lpg1496 (yellow), with important catalytic residues labeled for lpg1496. C, surface charge representation of the SidE domain (blue = positive, red = negative) with the bound ADP (gray). D, the SidE domain forms the most consistent polar contacts with the ribose ring of ADP. Two conserved histidines with LmjPDEB1 and human PDEs are involved in hydrogen bonds (His-370 and His-366).