[Accumulation of N-terminal fragment of recA protein in the htpR- mutant impairs the SOS-function of Escherichia coli cells].

It has been established that the plasmid encoding the N-terminal domain of RecA protein (50 amino acids residues) disturbs SOS functions of htpR- mutants of E. coli. This is expressed in increased UV-sensitivity of strains and in the poor transcription of the aminoglycosidephosphoransferase gene in the hybrid operon recA APT. The discovered effect is due to an increase in the stability of the peptide whose accumulation seems to impede the production of RecA protease. Mutation of gene lon does not lead to the accumulation of N-terminal fragment, therefore an increased stability of the peptide in htpR mutants is probably related to the absence of an unidentified peptidase.