Oligoribonucleotide initiators for herpes simplex virus DNA synthesis in vivo and in vitro

Abstract

Replicating herpes simplex virus (HSV) DNA, labeled with [ 3H]thymidine or [ 3H]uridine, was isolated from infected primary rabbit kidney cells. Nascent DNA strands are covalently linked to oligoribonucleotide stretches. The chain length of this RNA segment amounts to approximately 36 nucleotides wich are located at the terminus of the replicating DNA. The extent of RNA initiator synthesis seems to be closely correlated with the rate of HSV-DNA synthesis. The half life of the RNA initiator was estimated as 35 min. Evidence is presented by comparative studies regarding the characteristics of the naturally occurring RNA initiator, that cordycepin (3′-dAdo) is an inhibitor of the synthesis of the RNA initiator: (1) identical maximal chain length of the 3′-dAMP-RNA, (2) identical half-life of the 3′-dAMP-RNA segment, and (3) susceptibility to RNases and alkali. The 3′-dAMP-RNA segment is not covalently linked to HSV-DNA. HSV-Induced DNA polymerases utilizes not only deoxyribooligomers [ d(pA) 8 ] as initiators for the DNA template-dependent DNA polymerization. The initiating activity of both the DNA and the RNA segment is abolished when it carries a 3′-dAMP moiety at its 3′-terminus.