Identification of two herpes simplex virus type 1-induced proteins (21K and 22K) which interact specifically with the a sequence of herpes simplex virus DNA.

We have used a DNA competition binding assay to search for herpes simplex virus (HSV) proteins which are able to bind to specific sequences of the genome of HSV. Cloned DNAs from different regions of the virus genome were tested. Two late polypeptides, one major of apparent molecular weight 21 000 and one minor of 22 000, were preferentially bound by a variety of fragments containing the HSV-1 400 bp a sequence (a direct repeat present at the ends of the molecule and in inverted orientation between the long and short regions of the genome) but not by other competing DNAs including ones containing an origin of replication. We interpret our result as evidence that the HSV type 1-induced 21K and 22K polypeptides interact specifically with DNA sequences within this 400 bp HSV-1 a sequence.