FIG. 3.

Effect of overexpression of TBP and a dominant negative mutant on the activity of vaccinia virus intermediate I1L and late I2L promoters. Vaccinia virus-infected HeLa cells were transfected with reporter vectors driven by the I1L (panels A and B) or the I2L promoter (panels C and D) and cotransfected with the indicated amount of TBP expression vector or V169E TBP mutant expression vector. Panels B and D show the effect of block substitutions in the core element (ΔCE) or initiator element (ΔINR) on the reporter gene activity when cotransfected with 3 μg empty expression vector (−TBP) or 3 μg TBP expression vector (+TBP). WT, wild-type sequence promoter.