[Genetic engineering production of H37Rv M. tuberculosis proteins].

A complete library of M. tuberculosis H37Rv genes was produced by incorporating the DNA fragments of M. tuberculosis H37Rv into the lambda pSI phasmid.

[Metabolic regulation of the histidine operon in Escherichia coli and Salmonella typhimurium].

Expression of the histidine operon in Escherichia coli cells in contrast to the one in Salmonella typhimurium is changed proportionally to cells growth rate on the different carbon sources. The specific activity of histidinol-dehydrogenase is repressed by addition of 19 amino acids both in Escherichia coli and Salmonella typhimurium independent of the growth medium used. Using of Escherichia coli and Salmonella typhimurium strains containing the heterologous histidine operons made possible to demonstrate the dependence of the histidine operon metabolic regulation to be determined by the operon itself but not by the specificity of the recipient cells.

[Physico-chemical properties of the complexes of bacitracin with DNA and its effect on the process of transcription in vitro].

The aim of the present paper was to study the action of one of the peptide antibiotics, bacitracin, as the regulator of gene activity at the transcription level. Therefore the commercial bacitracin has been fractionated into two main parts by paper chromotography. These two fractions have been identified as bacitracin A (biologically active) and bacitracin F (biologically inactive).

[Dependence of threonine operon expression on the relA gene allelic state and the level of guanosine tetraphosphate in E. coli].

The expression of threonine operon in Rel+ and Rel- E. coli cells was studied at the transcriptional level. The rel+ genotype and the lack of a specific amino acid--threonine--are necessary for the stimulation of threonine operon transcription.