Identification of a RNA polymerase II initiation site in the long terminal repeat of Moloney murine leukemia viral DNA.

Abstract
A soluble in vitro RNA polymerase II transcription system was used to define the site of initiation of Moloney murine leukemia viral RNA synthesis. Molecularly cloned integrated and unintegrated Moloney murine leukemia virus DNA were used as templates. The 5'' ends of in vitro transcripts and virion RNA of Moloney murine leukemia virus were compared by nuclease S1 protection experiments. Viral sequences upstream of the in vivo cap site are implicated in the transcription of viral RNA and the 5'' end of an in vitro transcript derived from an integrated Moloney murine leukemia virus clone evidently corresponds to the 5'' end of viral genomic RNA.