[Effectiveness of expression of the chloramphenicol acetyltransferase gene controlled by foreign regulator regions in Escherichia coli cells. II. Molecular cloning of promoters].

The trpOP, lacUV5, tacOP, PR and PL-promotors were cloned in the previously obtained pML4 vector plasmid. The expression of structural gene cat was studied by the chloramphenicolacetyltransferase determination in cell extracts. The level of protein synthesis by appropriate recombinant plasmids was analysed in vivo and in vitro. It was shown that the efficiency of the gene expression is determined by both the "strength" of the promotors and mRNA translation specificity. The obtained collection of the plasmids might be used for the determination of the promotor strength by the hybridization of pulse-labeled mRNA with DNA and an effective expression of the genes by means of "hybrid protein gene" and "hybrid operon" constructions.