A simple and rapid method to obtain substitution mutations in Escherichia coli: isolation of a dam deletion/insertion mutation

Gene. 1988 Dec 20;73(2):531-5. doi: 10.1016/0378-1119(88)90517-3.


We describe the isolation of a strain of Escherichia coli bearing a deletion/insertion (i.e., a substitution mutation) in the dam gene (dam-16). The mutagenesis protocol used should be applicable to any cloned non-essential gene of E. coli. The substitution mutation confers resistance to kanamycin and can easily be transferred to other strains by standard genetic techniques. The amount of Dam methyltransferase (MTase) in dam-16 strains as determined either in vitro or in vivo is below the level of detection. We conclude that the Dam MTase is not required for viability of E. coli.

Publication types

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

MeSH terms

  • Chromosome Deletion*
  • Chromosome Mapping
  • Chromosomes, Bacterial
  • Crosses, Genetic
  • DNA Transposable Elements*
  • Escherichia coli / enzymology
  • Escherichia coli / genetics*
  • Genes*
  • Genes, Bacterial*
  • Genotype
  • Mutation*
  • Site-Specific DNA-Methyltransferase (Adenine-Specific) / genetics*
  • Transduction, Genetic


  • DNA Transposable Elements
  • Site-Specific DNA-Methyltransferase (Adenine-Specific)