[Cloning of recA and lexA genes on the plasmid with a broad host range]

The recA gene from Escherichia coli and Propionibacterium shermanii and lexA gene from E. coli were cloned of the plasmid pBI101 with a broad host range. The correlation of induction of the SOS function and the dose of UV-light, MMS and 4-NQO was studied in E. coli cells carrying the plasmid pJE43. The level of SOS response in recA cells carrying the plasmid pBI101::recA E. coli and pBI101::recA P. shermanii was higher than a SOS response level in EC1000 with a normal recA gene. However, no complete complementation of the SOS function was observed in recA cells when pBI101 with recA and lexA genes was incorporated and under the action of all mutagenic factors.