Eliminating the expression of the E8^E2 repressor protein further decreases the replication efficiency of HPV11 genomes unable to bind UAF1. (A) Southern blot analysis of total DNA extracted from U2OS cells transfected with HPV11 WT, UBS mut , E8 mut , and E8 mut UBS mut genomes. Total cellular DNA was extracted from HPV11-transfected U2OS cells 72 h posttransfection and digested prior to analysis with the single-cutter restriction enzyme HindIII and the methylation-sensitive restriction enzyme DpnI. The results are representative of 2 experiments. (B) Bar graph representing the replication efficiencies of different HPV11 genomes relative to the replication efficiency of the WT genome. Data represent quantitated Southern blot signals from 2 separate experiments; statistical significance was determined using ordinary one-way ANOVA followed by Dunnett's multiple-comparison test. Error bars represent the standard deviations.