Characteristics of chromatin preparations from herpes simplex virus infected cells

Chromatin isolated from herpes simplex virus type 1-infected baby hamster kidney cells contains a number of tightly associated virus-induced polypeptides. A subset of these proteins bind to immobilized DNA in vitro (Vmw 175, 155, 130, 63, 43, $\text{38}\text{39}$). Virus-induced polypeptides extractable with acid from infected cell chromatin include Vmw 155, the major capsid protein of herpes simplex virus type 1 virions, and Vmw 63 and $\text{38}\text{39}$ which are heterogeneous with respect to charge and are phosphorylated. These chromatin preparations, in the presence of deoxynucleoside triphosphates and MgCl₂ were capable of synthesizing viral and cell DNA in a reaction which was stimulated by the addition of ATP, riboNTPs and potassium acetate. In vitro synthesized viral DNA cosedimented with prelabelled parental DNA but the single-stranded product was smaller than parental DNA. Density labelling indicated that extensive synthesis was taking place and all BamHI fragments of viral DNA were represented by the DNA synthesized in vitro.