[Hybrid plasmid pSD1 containing the immunity region of bacteriophage lambda].

Hybrid plasmid pSD1 carrying the immunity region of the coliphage lambda and bio operon have been obtained by means of studying the efficiency of transcription DNA fragments in the plasmid RSF2124. The molecular weight of this plasmid is 17.2 Md. The growth inhibition of phage lambdavir has been observed in cells carrying the new hybrid plasma. The properties of the plasmid pSD1 and probable reasons of the growth inhibition of phage lambdavir are discussed. The hybrid plasmid pSD2 carrying genes R, A and J of phage lambda has been constructed on the basis of the plasmid RSF2124. There are cohesive ends in this plasmid which make possible its packing in the phage lambda head. Hybrid plasmid pSD3 carrying genes P and Q of phage lambda has also been constructed.