The early promoter of bacteriophage Mu: definition of the site of transcript initiation

Abstract
The early promoter of bacteriophage Mu has been Identified and characterized by a nitrocellulose filter binding assay and analysis of RNA products transcribed in vitro and in vivo. A tight, heparin resistant, RNA rolymeraee-DNA binding site overlaps the left Mu Hind III site. In vitro [λ32P] ATP initiated transcription begins approximately 25 nucleotides to the right of the Hind III restriction site. Dinucleotide Initiation with ApA and SI mapping of in vitro and in vivo transcripts shows that transcription is initiated 1028 base pairs from the Mu genetic left end.