ROLE OF WATER-MOLECULES AT CONSERVED POSITIONS NEAR THE ACTIVE-CENTEROF ASPARTIC PROTEINASES

Two absolutely conserved water molecules are localized in the close vi cinity to the active sites in the crystal structures of more than 30 n onretroviral aspartic proteinases and their complexes with inhibitors. The water molecules are part of the hydrogen bonding network involvin g active carboxyls. Our analysis suggests that these water molecules c an affect significantly the reactions catalyzed by aspartic proteinase s.