Sedimentation characteristics of newly synthesized Epstein-Barr viral DNA in superinfected cells.

Replicating Epstein-Barr virus (EBV) DNA molecules isolated from superinfected Raji cells were shown to consist of 80S to 65S and 58S (mature) molecules Pulse-chase experiments showed that radioactive label of DNAS molecules with the larger sedimentation coefficients was partially chased into 58S labeled forms. Formation of large concatemers of viral DNA could not be detected at any time after superinfection. The continuous presence of the 65S viral DNA intermediate throughout the replicative cycle combined with the observed inhibition of EBV DNA synthesis by addition of nontoxic levels of ethidium bromide to the superinfected cell culture led us to propose that EBV replication proceeds via a relaxed circular DNA intermediate.