LOCATION OF PROMOTER SITES ON PLASMID NTP1 WHICH CONTAINS THE AMPICILLIN RESISTANCE TRANSPOSON TN1701

We have modified the gene 32 protein electron microscopic method of Delius et al. (1973) so that promoter regions on covalently closed circular DNA templates may be mapped relative to specific restriction endonuclease cleavage sites. Using this method, four promoter regions have been located on the physical map of plasmid NTP1 at 0.01, 0.12, 0.33 and 0.45 NTP1 units. Transcription from all four promoters is to the right. Two of these promoters, at 0.01 and 0.12 NTP1 units, are located within the ampicillin resistance transposon recently designated Tn1701. The promoter located at 0.01 NTP1 units was found to be the strongest of the four promoters; it is proximal to the β-lactamase gene which is responsible for ampicillin resistance. © 1979.