Interaction of the adenoviral IVa2 protein with a truncated viral DNA packaging sequence

Adenoviral (Ad) infection typically poses little health risk for immunosufficient individuals. However, for immunocompromised individuals, such as AIDS patients and organ transplant recipients, especially pediatric heart transplant recipients. Ad infection is common and can be lethal. Ad DNA packaging is the process whereby the Ad genome becomes encapsulated by the viral capsid. Specific packaging is dependent upon the packaging sequence (PS), which is composed of seven repeated elements called A repeats. The Ad protein, IVa2, which is required for viral DNA packaging, has been shown to bind specifically to synthetic DNA probes containing A repeats I and 11, however, the molecular details of this interaction have not been investigated. In this work we have studied the binding of a truncated form of the IVa2 protein, that has previously been shown to be sufficient for virus viability, to a DNA probe containing A repeats I and II. We find that the IVa2 protein exists as a monomer in solution, and that a single IVa2 monomer binds to this DNA with high affinity (K-d