FIG. 4.

Specificity of repression of HPV-18 ori replication by exogenous YY1 protein. (A) Lane 1 contains a standard reaction mixture; the rest of the lanes contain the standard reaction mixture with the following additions: His-CAT protein (lanes 2 and 3), His-YY1 protein (lanes 4 and 5), anti-YY1 antibody (H414) raised against the intact YY1 protein (lane 6), and both YY1 and the H414 anti-YY1 antibody (lane 7). (B) Replication of pBSH18ori in 293 cell extracts supplemented with His-H18E1 alone (lane 1), GST-H18E2 alone (lane 2), or with both E1 and E2 proteins (lanes 4 to 6). To lane 5 was added exogenous his-YY1. Lane 6 contains both His-YY1 and antibody (C20) raised against the DNA-binding domain of the YY1 protein. Lane 3 contains the product of a replication reaction conducted with pBS cloning vector in 293 cells supplemented with both E1 and E2 proteins. The relative intensity (Rel I) values were calculated as percentages by comparing isotope incorporation to that in lane 1 (A) or lane 4 (B) as measured by a PhosphorImager. For both panels, the amounts (in μg) of protein or antibody added were as indicated.