Fig. 7.

Docked poses of atanyl blue PRL and acid blue 40 in the active site of UL98. Modeled molecular interactions of atanyl blue PRL (A) and acid blue 40 (B) (ligand – ball and stick representation; carbon – cyan) with the active site residues of UL98 (stick representation; carbon – green). The double-stranded DNA substrate is shown as transparent sticks (carbon – white) and the active-site Mg²⁺ ion shown as magenta sphere. H-bond interactions of the sulfonate with R164 and S252 of UL98 are shown as magenta dashed-lines and coordination interactions of metal ion with carboxylates of D254 and E278 of UL98 and the 9-position oxo group of ligand are shown as solid magenta lines. Lipophilic surface potential maps of the 4-position substitutions of atanyl blue PRL (C) and acid blue 40 (D) within the active site of UL98. The scale at the bottom indicates the color gradient – brown (lipophilic LP/hydrophobic) to blue (hydrophilic HP/polar). (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)