A 31-year-old man with AIDS complains of difficulty swallowing. Examination of his oral cavity demonstrates whitish membranes covering much of his tongue and palate. Endoscopy also reveals several whitish, ulcerated lesions in the esophagus. Which of the following enzymes converts the HIV genome into double-stranded DNA in host cells in the patient?

Reverse transcriptase. The primary etiologic agent of AIDS is HIV-1, an enveloped RNA retrovirus that contains a reverse transcriptase (RNA-dependent DNA polymerase). After it enters into the cytoplasm of a T lymphocyte, the virus is uncoated, and its RNA is copied into double-stranded DNA by retroviral reverse transcriptase. The DNA derived from the virus is integrated into the host genome by the viral integrase protein (choice C), thereby producing the latent proviral form of HIV-1. Viral genes are replicated along with host chromosomes and, therefore, persist for the life of the cell.Diagnosis: AIDS