Terminal redundancy and the origin of replication of Rous sarcoma virus RNA

Abstract

In vitro synthesis of Rous sarcoma virus DNA by the virion endogenous DNA polymerase activity is initiated on a tRNA(trp) primer located near the 5' end of the genome. A major product of such synthesis is a piece of DNA 101 nucleotides long (stron stop DNA) which can be isolated covalently bound to the tRNA primer. Here the strong stop DNA is complementary to the extreme 5' end of the genome. The 5' and 3' termini of the Rous sarcoma virus genome, excluding the cap and the poly(A), have the identical sequence. It is proposed that the function of this sequence is to facilitate elongation from the 3' end of DNA chains initiated elsewhere on the virus genome.