Chromosomal organization of the herpes simplex virus type 2 genome

Nucleoprotein complexes containing herpes simplex virus type 2 DNA were extracted from CV-1 cells with NP-40 and (NH₄)₂SO₄. The viral DNA-protein complex sedimented in neutral sucrose as a relatively homogeneous peak at around 120 S. Pooled material from the 120 S region of sucrose gradients contained DNA which, when deproteinized, sedimented at 55 S and had a density of 1.728 g/cm³ as expected for herpesvirus DNA. Buoyant density studies with glutaraldehyde-fixed complexes indicate that protein is bound to viral DNA at a ratio of approximately 1.1 to 1. Micrococcal nuclease digests of isolated viral nucleoprotein complexes indicate that these complexes do not have a nucleosomal structure. Chromatin prepared from nuclei following isolation of viral nucleoprotein complexes contained viral DNA. When infected nuclei were treated with micrococcal nuclease, nucleosome-sized fragments were obtained which contained both virus and cell DNA.