[Isolation and characterization of a phage T7 DNA fragment containing promoter B active in vivo and in vitro].

The fragment of 124 base pairs (Alu-124) has been isolated from the phage T7 DNA and cloned in the plasmid pSK. The sequence of the fragment was determined and position of this fragment on the physical map of phage DNA was found. It has been found that Alu-124 fragment contained an active in vivo and in vitro promoter for E. coli RNA-polymerase. In vitro transcription from this promoter was initiated with GTP. The start of the transcription was localised at about 104 or 105 nucleotide. The data obtained indicate that the Alu-124 fragment of the phage T7 promoter B, may be involved in the control of the transcription of the phage T7 early stage development.