Fig. 3.

General structures of constructs used to examine the roles of HIV-1 and HIV-2 Gag proteins in heterologous RNA copackaging. (A) HIV-1 constructs that do not express functional Gag. These constructs harbor a frameshift mutation in gag. (B) HIV-2 constructs that do not express functional Tat and Rev. These constructs harbor a frameshift mutation that simultaneously prevents expression of functional HIV-2 Tat and that of functional Rev. (C) HIV-2 constructs that do not express functional Gag and their DIS sequences. Each construct contains two mutations in gag to prevent expression of functional Gag. DIS sequences of the constructs are indicated. Frameshift mutations are indicated by asterisks.