NUCLEOTIDE-SEQUENCE ANALYSIS OF A 21-KBP REGION OF THE GENOME OF HUMAN HERPESVIRUS-6 CONTAINING HOMOLOGS OF HUMAN CYTOMEGALOVIRUS MAJOR IMMEDIATE-EARLY AND REPLICATION GENES

Human herpesvirus-6 (HHVB) is a CD4(+) T-lymphotropic herpesvirus that is a member of the betaherpesvirus subgroup. This laboratory has repo rted previously the results of large-scale sequence analyses of the HH V-6 genome and has identified putative immediate-early (IE) regulatory genes and associated transactivation functions. In this report I pres ent the sequence analysis of a 21-kbp region of the genome of HHV-6 st rain U1102 that is contiguous with the proximal region of the putative major IE (MIE) locus. Within this region (genomic positions 109-130 k bp) is a homologue of the human cytomegalovirus (HCMV) IE2 MIE gene (U L122), in addition to genes encoding probable virus DNA replication fu nctions. The latter include components of the helicase-primase complex , corresponding to HCMV UL102 and UL105 gene products, and a homologue of the origin binding protein conserved among the alphaherpesviruses. Several genes unique to HHV-6 also have been identified within the se quenced locus. These findings will contribute to efforts to identify a nd functionally characterize the complete repertoire of HHV-6 transcri ptional regulatory genes and will provide a basis for the further anal ysis of the molecular biology of this betaherpesvirus. (C) 1994 Academ ic Press, Inc.