FIG. 2.

Mutations in UL9 helicase motif Ia fail to complement the growth of UL9 null virus hr94. (A) Complementation indices for wild-type (WT) and mutant UL9 proteins. The transient transfection- complementation assay was performed as described in Materials and Methods. The complementation indices were calculated as a ratio of the viral titer from cells transfected with the wild-type or mutant version of UL9 gene to the viral titer observed when empty plasmid was transfected. The mean complementation index (means shown above the bars) and standard deviation (plotted as error bars) were calculated from three independent experiments. (B) Western blot analysis of the steady-state UL9 protein levels in cells transfected with wild-type (WT) or mutant UL9. The positions (in kilodaltons) of New England Biolabs prestained molecular size markers (MWM) are shown on the right.