CHARACTERIZATION OF THE N-15 LYSOGENIC CONVERSION GENE AND IDENTIFICATION OF ITS PRODUCT

The plasmids containing EcoRV fragments of N15 phage DNA and inhibiting the adsorption of T1, phi80 and N15 phages were selected and characterized. The N15 lysogenic conversion gene (cor) was mapped in the SalI-PstI fragment of 700 bp in length which is localized near SalI site with the coordinates 40.1 kb on the N15 plasmid prophage DNA physical map. The cor gene was recloned on a multicopy vector in the both possible orientations and its expression was shown to occur most probably wider control of its own promoter in the direction from SalI to the ClaI site of the SalI-PstI fragment. The molecular weight of the Cor protein (7-9 kD) was determined by the analysis in the system of mini-cells. Initiation of transcription to wards the cor gene from the external promoter led to the bacteriostatic effect.