FIGURE 6.

Polymerase processivity by the BMRF1 wild type (WT) and mutants. Long chain DNA synthesis was measured and visualized by alkaline-agarose gel electrophoresis of the products that incorporated radiolabeled dATP with a singly primed M13 single-stranded DNA (7.2 kb) as a primer-template by the EBV BALF5 polymerase (Pol) catalytic subunit. Reactions were conducted in the presence of the EBV BMRF1 mutants (lanes 2–10) or the wild type (WTΔC) (lane 11), or in the absence of the BMRF1 protein (lane 12). Replication assays were performed as described under “Experimental Procedures.” The replication products were visualized by autoradiography after electrophoresis on a 1.0% alkaline-agarose gel. Molecular size markers are heat-denatured 5′-terminally labeled HindIII fragments of λ DNA (lane 1). a.a., amino acids.