5' termini of poliovirus RNA: difference between virion and nonencapsidated 35S RNA

Abstract

Poliovirus cytoplasmic, nonencapsidated 35S RNA yields .apprx. 1 pUp/molecule upon T2 RNase digestion, indicating that this RNA has the same 5'' end as the polyribosome-associated viral RNA fraction. Double-stranded, replicative form RNA after the same treatment yielded .apprx. 4 pN[nucleoside]p structures/molecule, 65% of which was pUp. The 35S RNA from mature virions contained no detectable pNp, indicating that the 5'' end of the virion RNA is different from that of the nonencapsidated RNA. None of the above molecules contained pppNp, ppNp or GpppNp structures present in host [HeLa cells] mRNA. The virion RNA molecule, as shown previously for the nonencapsidated 35S viral RNA, is not labeled with [methyl-3H]methionine.