Previous Article | Next Article ![]()
J. Virol., Jan 1998, 48-56, Vol 72, No. 1
MA McVoy, DE Nixon, SP Adler and ES Mocarski
The DNA sequence motifs pac1 [an A-rich region flanked by poly(C) runs] and
pac2 (CGCGGCG near an A-rich region) are conserved near herpesvirus genomic
termini and are believed to mediate cleavage of genomes from replicative
concatemers. To determine their importance in the cleavage process, we
constructed a number of recombinant murine cytomegaloviruses with a second
cleavage site inserted at an ectopic location within the viral genome.
Cleavage at a wild-type ectopic site occurred as frequently as at the
natural cleavage site, whereas mutation of this ectopic site revealed that
some of the conserved motifs of pac1 and pac2 were essential for cleavage
whereas others were not. Within pac1, the left poly(C) region was very
important for cleavage and packaging but the A-rich region was not. Within
pac2, the A-rich region and adjacent sequences were essential for cleavage
and packaging and the CGCGGCG region contributed to, but was not strictly
essential for, efficient cleavage and packaging. A second A-rich region was
not important at all. Furthermore, mutations that prevented cleavage also
blocked duplication and deletion of the murine cytomegalovirus 30-bp
terminal repeat at the ectopic site, suggesting that repeat duplication and
deletion are consequences of cleavage. Given that the processes of genome
cleavage and packaging appear to be highly conserved among herpesviruses,
these findings should be relevant to other members of this family.
Copyright © 1998, American Society for Microbiology
Sequences within the herpesvirus-conserved pac1 and pac2 motifs are required for cleavage and packaging of the murine cytomegalovirus genome
Department of Pediatrics, Medical College of Virginia, Virginia Commonwealth University, Richmond 23298-0163, USA. mmcvoy@gems.vcu.edu
This article has been cited by other articles:
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»