Anatomy and pathology of HIV-1 peptidase.

The peptidase of the HIV type 1 (HIV PR) is required for the replication of and further infection by the virus. A concerted effort has taken place in the past 15 years to understand the properties of this enzyme, as it serves as an excellent drug target for control of the virus. Owing to drug pressure, many mutations arise during turnover of the virus and some of these lead to resistance to the effects of the inhibitors. Recent advances in the understanding of the changes these mutations cause to the enzyme and its interaction with substrates and inhibitors have been described. In addition, studies of closely related retroviral enzymes from simian immunodeficiency virus, feline immunodeficiency virus and HIV-2 have expanded the structure-function paradigm. The role of the flexibility of ligands and of the enzyme in active-site interactions is discussed.