A multisite-directed mutagenesis using T7 DNA polymerase: application for reconstructing a mammalian gene

Gene. 1988 Sep 15;69(1):81-9. doi: 10.1016/0378-1119(88)90380-0.


A method to introduce multiple mutations and to reconstruct genes, using a single oligodeoxyribonucleotide and DNA polymerase with high processivity, such as modified T7 DNA polymerase [Tabor and Richardson, Proc. Natl. Acad. Sci. USA 84 (1987a) 4767-4771], is described. A eukaryotic cDNA, coding for porcine growth hormone (pGH), was reconstructed in this study to delete 75 bp and to introduce a G----A transition. The deletion removes 75 bp and brings an ATG just upstream from the codon for the first amino acid in the mature protein. Moreover, the G----A substitution creates a new PvuII restriction site to facilitate further manipulation of the gene. Maximum mutation frequency with this multisite-directed mutagenesis is reached within 15 min with an efficiency approaching 50%, when using the modified T7 DNA polymerase. No multisite-directed mutants were obtained when T4 DNA polymerase or Klenow (large) fragment of DNA polymerase I were used. The described method is also applicable to simple single site-directed mutations as well as to more complex gene reconstruction strategies.

Publication types

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

MeSH terms

  • Animals
  • Base Sequence
  • Chromosome Deletion
  • DNA-Directed DNA Polymerase / metabolism*
  • Genes*
  • Growth Hormone / genetics*
  • Molecular Sequence Data
  • Mutation*
  • Oligonucleotide Probes
  • Pituitary Gland / metabolism
  • Plasmids
  • Restriction Mapping
  • Swine
  • T-Phages / enzymology*


  • Oligonucleotide Probes
  • Growth Hormone
  • DNA-Directed DNA Polymerase

Associated data

  • GENBANK/M22761