Interaction of herpes simplex virus 1 origin-binding protein with DNA polymerase α

The herpes simplex virus 1 (HSV-1) genome encodes seven polypeptides that are required for its replication. These include a heterodimeric DNA polymerase, a single-strand-DNA-binding protein, a heterotrimeric helicase/primase, and a protein (UL9 protein) that hinds specifically to an HSV-1 origin of replication (ori(s)). We demonstrate here that UL9 protein interacts specifically with the 180-kDa catalytic subunit of the cellular DNA polymerase α-primase. This interaction can be detected by immunoprecipitation with antibodies directed against either of these proteins, by gel mobility shift of an ori(s)-UL9 protein complex, and by stimulation of DNA polymerase activity by the UL9 protein. These findings suggest thai enzymes required for cellular DNA replication also participate in HSV-1 DNA replication.