Partial resistance of D64N/D116N IN active site mutant virus to MxB restriction. (A) Levels of NC mutant H23C, RT mutant V148I, and IN mutant D167K and D64N/D116N infectivities, normalized to the WT based on input levels of exogenous RT activity, in control (dark grey) versus MxB-expressing (light grey) cells. Results are plotted relative to the WT virus in control cells (set at 100%). (B) The re-plot of panel A results highlights the infectivities of the indicated viruses in MxB-expressing cells relative to control cells. (C) RT-normalized levels of D64N/D116N IN mutant infectivities with versus without additional CA mutations in control (dark grey) versus MxB-expressing (light grey) cells. The infectivity of the WT CA, D64N/D116N IN mutant virus in control cells was set to 100%. (D) Extent of MxB restriction of WT and CA mutant viruses that carry WT (dark grey) or D64N/D116N (NN) mutant IN (white bars). Results are an average of 5 independent experiments, with error bars denoting 95% confidence intervals.