UV INDUCTION OF THE LT-TOXIN OPERON WITH RESPECT TO THE GENES LEXA, RECA AND UMUD

UV induction of the elt operon (the LT-toxin operon in Escherichia col i) was demonstrated in experiments using fusion of elt::lac operons wi th the help of Mudl (Ap lac) phage. UV induction of the elt operon is lexA-dependent; thus, the possibility of SOS regulation of this proces s may be assumed. However, UV induction of the elt operon turned out t o be recA-independent, which makes it impossible to consider this indu ction as a typical SOS response. UV induction of the elt operon is als o observed in Salmonella typhimurium, which differs from E. coli in th e product of umuD, which suggests that the UV induction of the elt ope ron is umuD independent.