Figure 3 Active site. (a) The difference electron-density map
for DSP18 was generated with the final model, omitting the bound
HEPES. The stereo map contoured at the 3.0 level
was presented as superposed with the refined model. The
hydrogen-bonding interactions around the active site are
represented by dashed lines. (b) Electrostatic potential
surfaces of DSP18 and VHR (PDB code 1vhr ) are presented.
Positive and negative potentials are coloured blue and red,
respectively. Residues near the active site are labelled.
The above figure is reprinted
by permission from the IUCr:
Acta Crystallogr D Biol Crystallogr