Genetic content of a 20.9 kb segment of human herpesvirus 6B strain Z29 spanning the homologs of human herpesvirus 6A genes U40-57 and containing the origin of DNA replication.
A continuous 20.9 kb sequence from human herpesvirus 6 variant B (HHV-6B) strain Z29 (GenBank accession number L16947) is genetically colinear with a discrete segment of the human cytomegalovirus (HCMV) UL region and with HHV-6 variant A (HHV-6A). Short nucleotide sequence determinations at multiple sites within an 8.5 kb region immediately 3' to the 20.9 kb contig revealed additional colinearity between HHV-6B, HCMV and HHV-6A. Homology studies with the predicted peptide sequences from 11 complete and 12 partial HHV-6B open reading frames (ORFs) revealed that most encode proteins conserved to varying degrees in all previously sequenced primate herpesviruses. HHV-6B homologs were identified for the HSV-1 ICP18.5, ICP8, UL52, UL24, UL25 and major capsid protein. Several HHV-6B proteins had limited amino acid similarity to their positional homologs in other herpesviruses. Each gene identified is highly homologous to its HHV-6A counterpart, including two unique HHV-6 genes predicted to encode membrane-associated glycoproteins. However, two regions of substantial divergence were noted, one spanning the origin of replication and the other encoding one of the putative HHV-6-specific glycoprotein genes. Substitutions in the latter region lead to predicted differences in reading frames and protein lengths among HHV-6 isolates.
Lindquester
G J
GJ
Department of Biology, Rhodes College, Memphis, Tennessee, USA.
O'Brian
J J
JJ
Anton
E D
ED
Greenamoyer
C A
CA
Pellett
P E
PE
Dambaugh
T R
TR
D000595:Amino Acid Sequence; D001483:Base Sequence; D002213:Capsid / Q000235:genetics*; D004261:DNA Replication / Q000235:genetics*; D005814:Genes, Viral; D015654:Herpesvirus 6, Human / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D017421:Sequence Analysis