HIV Virus

**Retroviruses**, such as **HIV**, have an RNA genome that must undergo reverse transcription into DNA before being incorporated into the host cell's genome. They are categorized in group VI of the Baltimore classification scheme. To convert RNA into DNA, retroviruses possess genes that encode the virus-specific enzyme reverse transcriptase, which transcribes an RNA template into DNA. In uninfected host cells, reverse transcription does not occur, as the necessary reverse transcriptase enzyme is produced only from viral genes expressed within infected cells. HIV’s ability to produce certain enzymes unique to the virus has enabled researchers to develop drugs that specifically target these enzymes. For example, the reverse transcriptase inhibitor AZT inhibits HIV replication by decreasing the activity of the enzyme without interfering with the host cell's metabolism. This targeted approach has led to the development of a range of drugs for HIV treatment and has been effective at reducing the number of infectious virions (viral RNA copies) in the blood to undetectable levels in many individuals with HIV. *LICENSES AND ATTRIBUTIONS CC licensed content, Shared previously, Virus Infections and Hosts, Authored by: OpenStax College. License: CC BY: Attribution. License Terms: Download for free at http://cnx.org/contents/GFy_h8cu@9.85:fL0VrVv_@3/Virus-Infections-and-Hosts*