%0 Journal Article %A Neipel, Frank %A Ellinger, Klaus %A Fleckenstein, Bernhard %T The unique region of the human herpesvirus 6 genome is essentially collinear with the Ul segment of human cytomegalovirus %D 1991 %J Journal of General Virology, %V 72 %N 9 %P 2293-2297 %@ 1465-2099 %R https://doi.org/10.1099/0022-1317-72-9-2293 %I Microbiology Society, %X The entire genome of human herpesvirus 6 (HHV-6) strain U1102 was cloned as overlapping fragments in cosmid and plasmid vectors. Cleavage maps were constructed for the restriction endonucleases BamHI, EcoRI, NotI and SmaI. The genome of HHV-6 U1102 is a linear dsDNA of 163 kbp, consisting of a long unique 142 kbp region flanked by direct terminal repeats of 10.5 kbp. Short stretches (290 to 470 nucleotides) of DNA, four from the terminal repeats and 55 from the U l region, were sequenced and compared by computer with the known herpesvirus amino acid sequences. Homologies were found for 10 open reading frames that are scattered over the U l region of HHV-6. Their relative positions and orientations indicate that the unique region of HHV-6 is essentially collinear with the U l region of human cytomegalovirus (HCMV), but is not collinear with the other human herpesviruses. It confirms and extends earlier observations that HHV-6 is more closely related to the β-herpesvirus HCMV, suggesting that HHV-6 may be considered as the prototype of a new β2-herpesvirus subgroup. %U https://www.microbiologyresearch.org/content/journal/jgv/10.1099/0022-1317-72-9-2293