DNA base sequence of the po promoter region of phage λ

Abstract
The sequence of a 123 base pair HpaII restriction [endonuclease] fragment of bacteriophage .lambda. DNA was determined by the dimethylsulfate-hydrazine technique. Of this fragment 65 nucleotide pairs are transcribed into the 5'' proximal part of the oop RNA [a primer in the initiation of .lambda. DNA]. The remaining 58 nucleotide pairs preceding the start point of transcription show homologies to the .lambda.pL and .lambda.pR promoter regions and apparently contain the .lambda.pO promoter sequence.