Association of the herpes simplex virus regulatory protein ICP4 with specific nucleotide sequences in DNA.

We report that the herpes simplex virus (HSV) transcription regulatory protein designated ICP4 is a component of a stable complex between protein and specific nucleotide sequences in double-stranded DNA formed by addition of exogenous DNA to either a crude extract obtained from HSV-1 infected cells or a partially purified preparation of native ICP4. DNA sites which are bound directly or indirectly to ICP4 have been designated ICP4/protein binding sites. Three independent ICP4/protein binding sites have been identified by DNAse footprinting; two are in the vector pBR322 and one is located approximately 100 nucleotides upstream from the HSV glycoprotein D mRNA cap site. Comparison of the nucleotide sequences in these three sites reveals several regions of homology. We propose that the sequence 5'-ATCGTCNNNNYCGRC-3' (N = any base; Y = pyrimidine; R = purine) forms an essential component of the ICP4/protein binding site.