Fig 2.

Analysis of deletion mutants of UNG2 for modulation of HIV-1 mutation rate. (A) Schematic representation of the UNG2 deletion mutants expressed as fusions to the VprW54R mutant; amino acids are numbered according to the system of Haug et al. (15). (B) Viruses produced from cells expressing the deleted VprW54R-UNG2 fusions were assayed for mutant frequency phenotype as indicated in Fig. 1A. A total of 356 colonies were screened. and the average mutant frequency of the vpr-null mutant HIV-1 in the absence of Vpr transcomplementation was 0.15 (55/356) mutant/cycle. Values are the means of three independent experiments. Error bars represent one SD from the mean. (C) Virion incorporation of the VprW54R-UNG2 fusion proteins. 293T cells were cotransfected with a vpr-defective HIV-1-based vector in combination with plasmids for expression of HA-tagged VprW54R-UNG2 deleted fusions. Virions were collected from cell supernatants; proteins from cell and virion lysates were analyzed by Western blotting with anti-HA and anti-CAp24.