Adenoviruses (Ads) have a complex architecture with at least 12 structural proteins. The major protein, the hexon, is the main component of the capsid and there are a number of other capsomeres which complete the capsid and link with the core of the virus (Stewart et al., 1993). The latter consists of the viral double-stranded DNA genome in association with a number of other proteins -the principal ones being proteins VII and V as well as the small peptide mµ. The spatial organization of the core has been the subject of a number of studies, sometimes with conflicting conclusions (for reviews see Nermut, 1984 ;Vayda et al., 1983). Protein VII is a highly basic protein very tightly attached to the viral DNA and most likely plays a role analogous to histones in cellular chromatin. However, very little is known of its structure and function although some