TABLE 2.
Summary of the biochemical properties of selected UL54 mutants
| Mutation | Activitya
|
||
|---|---|---|---|
| UL44 binding | Basal DNA polymerase activity | Stimulation by UL44 | |
| F1217A | +/−a | +/− | − |
| R1224A | +/− | + | +/− |
| H1226A | +/− | + | +/− |
| L1227A | − | + | − |
| F1231A | − | + | − |
| F1231Y | + | + | + |
| L1232A | + | + | + |
| Y1234A | +/− | + | +/− |
| C1241A | + | + | + |
| C1242A | + | + | + |
| C1241A-C1242A | + | + | + |
| ΔCC | +/− | + | +/− |
a
+, Wild-type levels of activity; +/−, partially impaired activity; −, no detectable activity. Binding to UL44 was determined by GST-pulldown experiments (Fig. 6), basal DNA polymerase activity was tested in a filter-based assay (Fig. 9), and stimulation of long-chain DNA synthesis in the presence of UL44 was determined by analyzing the products on alkaline agarose gels (Fig. 8).