FIG. 3.

In vitro binding of immortalizing (left panel) and nonimmortalizing (right panel) HPV16 E6 mutants to hADA3. (A) Equal aliquots of in vitro-translated ³⁵S-labeled E6 proteins were allowed to bind to GST or GST-hADA3 (aa 75 to 432), and bound E6 proteins were then resolved by SDS-PAGE and visualized by fluorography. The input lane contains 10% of the aliquots used in the binding reactions. The numbers next to each lane indicate the percent binding compared to the input. Δ, Deletion. The immortalizing versus nonimmortalizing designation of each E6 mutant is derived from a mammary epithelial cell immortalization assay reported previously (12, 47). All mutant proteins are derivative of HPV16 E6. (B) The bottom panel shows Coomassie blue staining of the GST fusion proteins used in the binding reactions.