[para-Aminobenzoic acid inhibits the manifestation of inducible SOS functions in Escherichia coli K-12].

In experiments with chemical mutagens (alkylating agents MNU, ENU, MMS and EMS), para-aminobenzoic acid (PABA) sharply inhibited the inducible processes in Escherichia coli, namely, mutagenesis, induction of lambda prophage and W-reactivation of UV-irradiated phage lambda. Based on experimental studies of E. coli strains deficient in different steps of DNA repair, the conclusion was made that PABA participates in regulation of the branch of DNA repair that is controlled by recA+ recF+ alleles.