Blunt-end and single-strand ligations by Escherichia coli ligase: influence on an in vitro amplification scheme

Gene. 1990 Apr 30;89(1):117-22. doi: 10.1016/0378-1119(90)90213-b.


A ligase-based, in vitro DNA amplification system (LAR) has been described by Wu and Wallace [Genomics 4 (1989) 560-569]. This strategy is based on the ability of a DNA ligase to join the 5' phosphate of one DNA molecule to the 3' hydroxyl of a second during a nick-closing reaction. Escherichia coli DNA ligase has been used in place of the T4 DNA ligase in our study in order to limit template-independent ligation activities, which lower the sensitivity of this amplification procedure. The results of this study indicate that E. coli ligase also joins blunt-ended DNA molecules and some single-stranded oligodeoxyribonucleotides, in the absence of a complementary template, with an efficiency which is sensitive to both the concentrations of DNA substrate and enzyme.

MeSH terms

  • Base Sequence
  • DNA Ligases / metabolism*
  • Escherichia coli / enzymology*
  • Kinetics
  • Molecular Sequence Data
  • Nucleic Acid Amplification Techniques*
  • Oligonucleotide Probes
  • Polynucleotide Ligases / metabolism*
  • Substrate Specificity
  • T-Phages / enzymology


  • Oligonucleotide Probes
  • DNA Ligases
  • Polynucleotide Ligases