Human adenoviral DNA association with nucleosomes containing histone variant H3.3 during the early phase of infection is not dependent on viral transcription or replication.

Adenovirus (Ad) DNA undergoes dynamic changes in protein association as the virus progresses through its replicative cycle. Within the virion, the Ad DNA associates primarily with the virus-encoded, protamine-like protein VII. During the early phase of infection (similar to 6 h), the viral DNA showed declining association with VII, suggesting that VII was removed from at least some regions of the viral DNA. Within 6 h, the viral DNA was wrapped into a repeating nucleosome-like array containing the histone variant H3.3. Transcription elongation was not required to strip VII from the viral DNA or for deposition of H3.3. H3.1 did not associate with the viral DNA at any point during infection. During the late phase of infection (i.e., active DNA replication similar to 12-24 h), association with H3 was dramatically reduced and the repeating nucleosome-like pattern was no longer evident. Thus, we have uncovered some of the changes in nucleoprotein structure that occur during lytic Ad infection.