Fig. 1

Diagrammatic representation of the HTV-1 genome.

The long terminal repeats (LTRs), divided into the unique 3′ (U3), repeat (R), and unique 5′ (U5) domains, flank the protein encoding regions of the virus genome (light blue). The large precursor proteins encoded by the capsid (GAG), polymerase (POL), and envelope (ENV) genes are proteolytically cleaved as depicted by the vertical lines. The GAG protein is cleaved into the smaller proteins p17, p24, and p6; the POL protein is cleaved into the protease (PR), reverse transcriptase (RT), and integrase (IN) proteins; and the ENV protein, with a signal peptide (S.P.) sequence at the amino terminus, is cleaved into the gp 120 (surface) and gp41 (transmembrane) proteins. Exons (EX) 1 and 2 of the rev and tat genes as well as the genes encoding the accessory proteins are highlighted by color.