Venue: Room A202, Institute of Microbiology, Chinese Academy of Sciences
Abstract:Viruses have been found to employ diverse replication strategies. In contrast to the two well-defined re2plication modes employed by some viruses, the θ replication and the σ replication, much less is known about the more complex replication involving multimeric and highly branched viral replicative intermediates. Here, we describe a novel replication strategy exploited by the crenarchaeal rudivirus SIRV2 carrying linear dsDNA with hairpin ends. We find that SIRV2 forms large, multimeric and branched replication intermediates with unusual “mop-like” structures, resulted from strand-displacement replication with multiple consecutive reinitiation events from one parental template. Moreover, our data suggest the involvement of a diversity of replication modes in SIRV2 replication including strand-displacement from both termini of the linear dsDNA genome, rolling-circle mode of replication and bidirectional replication from a circular dimeric intermediate. Further, SIRV2 forms replication centers in the infected host cells where host replication proteins such as DNA polymerase DpoI and PCNA concentrate, mimicking eukaryotic viral factories.