Selects the target DNA sites for transposition. Recruits DDE-recombinase A to the target sites and catalytically activates it. Displays non-specific DNA-binding properties. Polymerizes as helical filaments around the DNA. Coating of the DNA by the target DNA activator B might play a role in favoring target-primed replication over integration. Prevents self-integration into an integrated copy of the viral genome. This mechanism is called target immunity and is achieved by two mechanisms: first, the target DNA activator B dissociates from the viral genome ends upon interaction in cis with DDE-recombinase A, which makes the viral genome ends a poor target for new insertions. Second, the interior of the viral genome may also be protected from integration events by the target DNA activator B being strongly bound throughout the whole viral genome (By similarity). ATP + H2O = ADP + H(+) + phosphate Homomultimer. Polymerizes in presence of ATP, preferentially on DNA. ATP hydrolysis triggers polymers dissassembly. Interacts with DDE-recombinase A; this interaction stimulates the catalytic activity of the latter as well as the ATPase activity of MuB followed by its dissociation from DNA (By similarity). Expressed in the early phase of the viral replicative cycle. Expression of early genes is repressed by viral Repc (latency) and favored by viral Ner protein. The N-terminus region contains a putative DNA-binding region that allows filament-filament interactions and probably favors MuB polymerization and filament clustering (By similarity). The central region contains the ATPase module (By similarity). The C-terminus comprises four helices arranged in a loosely packed bundle which can bind to dsDNA (By similarity). Belongs to the AAA ATPase family.