Figure 4

HBx expression increases the UV sensitivity of yeast cells. (A) UV survival profile of HBx expressing yeast cells. Saturated yeast cultures of strain 334 containing plasmids, pYES and pYES-X^wt and pYES-X^muts (as indicated), were diluted in water and plated on YMIN plates containing 2% glucose, 2% glycerol, 2% ethanol and 2% galactose (for induction of HBx). Cells were immediately irradiated under a germicidal lamp. Plates were then incubated in dark for at least 24 hrs and shifted to 30°C. Colonies were counted to determine the survival fraction. This is the average of three experiments. The ordinate represents the survival fraction, while the abscissa displays the dosage of UV irradiation. (B) UV survival profile of HBx expression in TFIIH mutant yeast cells. This is the average of three experiments. The ordinate represents the survival fraction, while the abscissa displays the dosage of UV irradiation.