[Expression of gene recA of Deinococcus radiodurans in Escherichia coli cells].

Plasmids pKS5 and pKSrec30 carrying normal and mutant alleles of Deinococcus radiodurans recA gene controlled by the lactose promoter slightly increase radioresistance of Escherichia coli cells with mutations at genes recA and ssb. The RecA protein of D. radiodurans is expressed in E. coli cells, and its synthesis can be supplementary induced. The radioprotective effect of the xenologic protein does not exceed 1.5 times and is essentially to the contribution of plasmid pUC 19-recA1.1 harboring the E. coli recA+ gene in the recovery of resistance of the deltarecA deletion mutant. These data suggest that the expression of D. radiodurans recA gene in E. coli cells does not complement mutations at gene recA in the chromosome possibly due to structural and functional peculiarities of the D. radiodurans RecA protein.