Retroviral reverse transcriptase: synthesis, structure, and function.

The virion particles of all retroviruses contain reverse transcriptase, a multifunctional enzyme required for the synthesis of a DNA copy of the viral RNA genome soon after entry into the infected cell. The enzyme is the target of the major antiviral drugs currently in use in the treatment of AIDS. This article reviews the strategies used by different retroviruses for the synthesis of the enzyme; the structure of the enzymes encoded by various viruses; the activities inherent in the enzyme; and the application of those activities to the process of reverse transcription of the viral RNA.