Practice question

Human immunodeficiency virus type 1 possesses lentiviral genome unique among retroviruses for efficient targeting of non-dividing cells. Encapsidated within conical capsid are two identical, non-covalently linked copies of ~9.2 kb positive-sense RNA capped and polyadenylated, bonded at dimer linkage structure near 5' end. Diploidy facilitates recombination and complementation of defects. Each RNA associates with nucleocapsid protein, reverse transcriptase and integrase. After entry, reverse transcriptase copies one RNA into double-stranded proviral DNA integrated into host chromosome by integrase, establishing persistent infection hallmarked by high mutation rate.