IDENTIFICATION OF A LYTIC-PHASE ORIGIN OF DNA-REPLICATION IN HUMAN HERPESVIRUS-6B STRAIN-Z29

DNA sequences which have structural features suggestive of their funct ioning as an origin of lytic-phase DNA replication were previously ide ntified in both human herpesvirus 6B strain Z29 [HHV-6B (Z29)] and in HHV-6A (U1102). Plasmid constructs containing the putative HHV-6B (Z29 ) oriLyt element were replicated after transfection into permissive T cells, when trans-acting factors were provided by HHV-6B (R-1) infecti on. By using this assay, the HHV-6B (Z29) oriLyt was mapped to a minim al region of approximately 400 bp which lies upstream of the gene that is homologous to herpes simplex virus UL29, a region that carries an origin in other betaherpesviruses and in some alphaherpesviruses.