Retrovirus
A retrovirus is a type of virus that uses RNA as its genetic material. Upon infecting a cell, a retrovirus uses an enzyme called reverse transcriptase to convert its RNA into DNA. The retroviral DNA is then integrated into the DNA of the host cell, allowing the retrovirus to replicate. Many retroviruses are associated with diseases, including AIDS and some forms of cancer.
Retroviruses are named for a special enzyme thats a vital part of their life cycle — reverse transcriptase. They are classified into two groups: Group VI, which includes single-stranded RNA viruses with a DNA intermediate in their life cycle, and Group VII, which includes double-stranded DNA viruses with an RNA intermediate in their life cycle.
Three retroviruses can cause illness in humans: Human Immunodeficiency Virus (HIV), Human T-Lymphotropic Virus type I (HTLV-I), and Human T-Lymphotropic Virus type II (HTLV-II). HIV is the virus that causes AIDS, while HTLV-I causes some forms of leukemia and lymphoma.
