Mg and Mn are critical cofactors in the integration phase.  Inactivating these cofactors (e.g. through chelation) causes functional impairment of IN. This concept gives researchers the opportunity to design and develop highly efficient IN inhibitors (INIs). In fact, all small molecule HIV-1 INIs that are now being researched contain a structural motif that coordinates the two divalent magnesium ions in the enzyme's active site.
Raltegravir and elvitegravir share the same mechanism of action against integrase: to bind to the active site of Mg ions. Competitive inhibitors compete directly with viral DNA for binding to integrase in order to inhibit 3‘-end processing. In doing this the inhibitors completely block the active site from binding to target DNA. This inhibition is called strand transfer inhibition.