FIG. 4.
Integration by HXB-IND64V viruses that contain N- and C-terminally truncated integrase proteins fused to LexA. (A) A 50-ng p24 equivalent was used to infect each of the representative plates shown for the hygromycin resistance assay. One million HeLa-CD4 cells were infected for 4 h with viruses containing the Vpr fusion proteins R-IN (c), R-IN50-288/LA (d), or R-IN1-234/LA (e). A positive control virus (WT) (a) and a negative control virus (D64V) (b) were also assessed. At 2 days after infection, the cells were grown in 200 μg of hygromycin B per ml for 12 days. (B) Graphical representation of the average of three independent experiments for infectivity and integration by the HXB-IND64V virus containing IN50-288/LA or IN1-234/LA. Each experiment was conducted with each of 50-, 5-, and 0.5-ng p24 equivalents of the indicated virus in the hygromycin resistance assay. An average of 1,200 colonies were counted on plates infected with 50-ng p24 equivalent of the positive-control, wild-type virus.