THE PRODUCT OF THE UL6 GENE OF HERPES-SIMPLEX VIRUS TYPE-1 IS ASSOCIATED WITH VIRUS CAPSIDS

We report on the analysis of the UL6 and UL7 open reading frames of th e herpes simplex virus type 1 (HSV-1) genome. The UL6 and UL7 transcri pts were identified in HSV-1-infected cells by Northern blotting and s hown to be coterminal at their 3' ends. Both transcripts were synthesi zed in the presence of phosphonoacetic acid, although in reduced amoun ts, indicating that UL6 and UL7 are expressed as delayed-early or gamm a-1 genes. The 5' ends of the two transcripts were mapped by S1 nuclea se and primer extension analysis. A polyclonal antiserum directed agai nst an Escherichia coli-expressed 6x His-UL6 fusion protein identified a protein of approximate M(r) 75,000 in cells infected with either HS V-1 or with a vaccinia virus recombinant expressing the HSV-1 UL6 prot ein. As with the transcript, the UL6 protein was synthesized at reduce d levels in the absence of viral DNA replication. Western immunoblotti ng showed that the UL6 protein was present in purified virions but not in L-particles of HSV-1, and that it was located exclusively in the t egument/capsid fraction of virion. Further analysis of the UL6 protein revealed that this protein was associated with virus capsids. (C) 199 5 Academic Press, Inc.