Viability of Escherichia coli K-12 DNA adenine methylase (dam) mutants requires increased expression of specific genes in the SOS regulon

Mol Gen Genet. 1985;201(1):14-9. doi: 10.1007/BF00397979.

Abstract

We have examined the level of expression of the SOS regulon in cells lacking DNA adenine methylase activity (dam-). Mud (Ap, lac) fusions to several SOS operons (recA, lexA, uvrA, uvrB, uvrD, sulA, dinD and dinF) were found to express higher levels of beta-galactosidase in dam- strains than in isogenic dam+ strains. The attempted construction of dam- strains that were also mutant in one of several SOS genes indicated that the viability of methylase-deficient strains correlates with the inactivation of the SOS repressor (LexA protein). Consistent with this, the wild-type functions of two LexA-repressed genes (recA and ruv) appear to be required for dam- strain viability.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • DNA Repair*
  • DNA, Bacterial / genetics*
  • Escherichia coli / enzymology
  • Escherichia coli / genetics*
  • Escherichia coli / growth & development
  • Genes*
  • Genes, Bacterial*
  • Genotype
  • Methyltransferases / genetics*
  • Mutation*
  • Rec A Recombinases / genetics
  • Site-Specific DNA-Methyltransferase (Adenine-Specific)
  • Species Specificity
  • Transduction, Genetic
  • beta-Galactosidase / genetics

Substances

  • DNA, Bacterial
  • Methyltransferases
  • Site-Specific DNA-Methyltransferase (Adenine-Specific)
  • Rec A Recombinases
  • beta-Galactosidase