FIG. 5.
Conserved motifs between Vif proteins from HIV-2 are essential for viral infectivity. (A) Genetic structure of Vif2 mutant proteins constructed by site-direct mutagenesis by altering the conserved motifs of HIV-2 Vif proteins. Mutant vif genes were introduced into the proviral clone HIV-2ROD. Mutant Vif STOP was made by altering the sequence of amino acids 51 and 52 (TGGTGG) for stop codons (TGATGA). HIV-2RODMD1A and HIV-2RODMD1B are deletion mutants in the first conserved motif of Vif2 protein (amino acids 42 to 61). HIV-2RODMD1A has a deletion from amino acid residues 42 to 50 and HIV-2RODMD1B from residues 50 to 61 of Vif2. HIV-2RODM2 is a mutant generated in the second conserved region of Vif2 (amino acids 122 to 130) by substitution of Arg124, Arg125 and Arg128 to alanine. (B) Viral replication kinetics of HIV-2 wild-type, HIV-2RODSTOP, HIV-2RODMD1A, HIV-2RODMD1B and HIV-2RODM2. PBMC, A3.01, H9, U38 and Jurkat cells were infected with recombinant viruses as described in Materials and Methods. Cell-free supernatants collected at different time points were subjected to p26 antigen assay. The data are expressed as means of at least three independent experiments ± the standard deviations.