Structural highlights
Function
TNPA_BPMU Responsible for viral genome integration into the host chromosome. During integration of the incoming virus, DDE-recombinase A cleaves both viral DNA ends and the resulting 3'-OH perform a nucleophilic attack of the host DNA. The 5' flanking DNA attached to the ends of the viral genome (flaps) are resected by the DDE-recombinase A endonuclease activity, with the help of host chaperone ClpX. The gaps created in the host chromosome by the viral genome insertion are repaired by the host primary machinery for double-strand break repair. Responsible for replication of the viral genome by replicative transposition. During replicative transposition, DDE-recombinase A is part of the transpososome complex. DDE-recombinase A cleaves the viral DNA and the resulting 3'-OH performs a nucleophilic attack of the host DNA. The 5' flanking DNA is not resected and an intermediary structure is formed. This structure is resolved by target-primed replication leading to two copies of the viral genome (the original one and the copied one). Host ClpX and translation initiation factor IF2 play an essential transpososome-remodeling role by releasing the block between transposition and DNA replication. Successive rounds of replicative transposition can lead up to 100 copies of the viral genome. Promotes replication and thereby lytic development by competing with repressor c (Repc) for binding to the internal activation sequence (IAS) in the enhancer/operator region. The outcome of this competition determines if the virus enters latency or starts replication.
See Also
