DNA base sequence of the po promoter region of phage lamdba.

The sequence of a 123 base pair HpaII restriction fragment of bacteriophage lamdba DNA has been determined by the dimethylsulphate-hydrazine technique. Of this fragment 65 nucleotide pairs are transcribed into the 5' proximal part of the oop RNA. The remaining 58 nucleotide pairs preceding the start point of transcription show homologies to the lamdbaL and lamdbapR promoter regions, and are concluded to contain the lamdbapo promoter sequence.