[Cloning of the promoter of the RNA polymerase operon located before the structural gene of the beta-subunit].

An EcoRI-fragment of the rpoBC operon carrying the end of the rplL gene, the intercistron region and the beginning of the rpoB gene cloned on the pBRH4 plasmid makes it tetracyclin-resistant, i. e. possesses the properties of a promoter. There is no appreciable difference in the degree of antibiotic resistance of recombinant plasmids carrying the main PJ promoter and the additional promoter.