FIG 6.

Inhibition of RTC DNA synthesis by Nullbasic. HIV-1 was produced by cotransfection of a proviral plasmid with a Nullbasic-FLAG expression plasmid (■) or an empty expression plasmid (■) as described in Materials and Methods. HEK293T cells were infected with VSV-G-pseudotyped HIV-1. Cell lysates were prepared 4 h postinfection and layered on top of a 20 to 70% linear sucrose gradient. After centrifugation, fractions were collected from the bottom and the density of each fraction was measured (dashed line). A sample from each fraction was assayed for HIV-1 −sssDNA by qPCR (top graph) and for CAp24 by ELISA (bottom graph). The experiment was repeated twice with similar results, and the results of a representative experiment are shown.