The initial nucleotide sequence of DNA transcribed from avian myeloblastosis virus 70 S RNA by RNA-dependent DNA polymerase

Denaturation of avian myeloblastosis virus 70 S RNA resulted in the release of one major and several minor species of 4 S RNA which were separated by electrophoresis in polyacrylamide gels. The major 4 S RNA component (one to two molecules per 70 S RNA) was shown to function in the 70 S RNA complex as the primer for the initiation of DNA synthesis in vitro by the viral RNA-dependent DNA polymerase. The covalent linkage between primer RNA's and nascent DNA's was found to involve an adenosine residue at the 3′-termini of the RNA's and a deoxyadenosine residue at the 5′-termini of the DNA's. By nearest neighbor analyses, a single unique nucleotide sequence, dApdApdTpdGpd-ApdApdGpdC OH, was determined to be present at the 5′-termini of the nascent DNA transcripts.