Etoposide docked into the <i>C</i>. <i>elegans</i> TOP-2 homology model.

<p>Etoposide docked into the (A) glutamine-containing Bristol TOP-2 enzyme (Δ<i>G</i> = -10.09 kcal/mol), (B) methionine-containing Hawaii TOP-2 enzyme (Δ<i>G</i> = -12.67 kcal/mol), and (C) the overlay of both structures. Glutamine is colored in orange, and methionine is colored in blue. Etoposide docked into the glutamine-containing TOP-2 enzyme is orange, and etoposide docked into the methionine-containing TOP-2 enzyme is blue. DNA is colored in gray, and the ribbon representation of the TOP-2 protein is shown in tan.