Structure of Cloned Retrovirus Circular DNAs: Implications for Virus Integration
This extract was created in the absence of an abstract.
Excerpt
During the multiplication cycle of retroviruses, double-stranded DNA reverse transcripts are produced, some of which integrate into the host-cell genome. Although the exact order of events preceding integration of the retroviral DNA is not known, certain potentially relevant steps have been described. The initial reverse transcript is a linear molecule containing a directly repeated sequence at each end (Gilboa et al. 1979a). These long terminal repeat (LTR) sequences range from 300 bp to 1200 bp (Shank et al. 1978a,b; Gilboa et al. 1979b) and contain an inverted repeat at each end (Sutcliff et al. 1980). The linear retroviral DNA molecules can enter the nucleus, whereupon some form circles (Shank and Varmus 1978) containing either one or two LTR sequences (Shank et al. 1978b; Yoshimura and Weinberg 1979). The circularization event may be a prerequisite to integration, since in mouse cells incompatible at Fv-1, linear retroviral DNA accumulates but circularization and...
