PMID: 7022127Jan 1, 1981

DNA sequence of a plasmid-encoded dihydrofolate reductase

Molecular & General Genetics : MGG
G SwiftF Heffron


The sequence of the methotrexate-resistant dihydrofolate reductase (DHFR) gene borne by the plasmid R-388 was determined. The gene was subcloned and mapped by an in vitro mutagenesis method involving insertion of synthetic oligonucleotide decamers encoding the BamHI recognition site. Sites of insertion that destroyed the methotrexate resistance fell in two regions separated by 300 bp within a 1.2 kb fragment. One of these regions encodes a 78 amino acid polypeptide homologous to another drug-resistant DHFR. The second region essential for DHFR expression appears to be the promoter of the DHFR gene.


Jun 1, 1991·Journal of Biotechnology·P S Vermersch, G N Bennett
Nov 1, 1987·Proceedings of the National Academy of Sciences of the United States of America·M OuelletteP H Roy
Mar 6, 2004·Microbial Drug Resistance : MDR : Mechanisms, Epidemiology, and Disease·Malin GrapeGöran Kronvall
May 10, 1985·Nucleic Acids Research·S MötschJ Grinsted
Jul 28, 2006·Antimicrobial Agents and Chemotherapy·Renee S LevingsR M Hall
Feb 13, 2008·Antimicrobial Agents and Chemotherapy·Carlos RevillaFernando de la Cruz
Jan 1, 1987·Antimicrobial Agents and Chemotherapy·Lars SundströmO Sköld
Oct 1, 1987·Antimicrobial Agents and Chemotherapy·P Huovinen
Sep 1, 1987·Antimicrobial Agents and Chemotherapy·I G Campbell, B J Mee
Nov 1, 1991·Antimicrobial Agents and Chemotherapy·Y ParsonsH W Stokes
Jun 1, 1993·Antimicrobial Agents and Chemotherapy·E HeikkiläP Huovinen
Jan 1, 1995·Antimicrobial Agents and Chemotherapy·C M Collis, R M Hall
Feb 1, 1995·Antimicrobial Agents and Chemotherapy·P HuovinenO Sköld
Sep 25, 2003·Antimicrobial Agents and Chemotherapy·Latefa Biskri, Didier Mazel
Dec 19, 2006·Journal of Bacteriology·Masaki ShintaniHideaki Nojiri
Mar 2, 2002·Journal of Bacteriology·Karin HanssonPaul H Roy
Feb 1, 1988·Molecular & General Genetics : MGG·E Martinez, Fernando de la Cruz
Sep 1, 1985·Plasmid·C R Valentine


Dec 2, 1975·Biochemistry·D BaccanariJ J Burchall
Jan 1, 1979·Annual Review of Genetics·M Rosenberg, D Court
Dec 1, 1978·Proceedings of the National Academy of Sciences of the United States of America·F HeffronB J McCarthy
Mar 18, 1972·British Medical Journal·M P FlemingR N Grüneberg
Jan 1, 1973·Annual Review of Biochemistry·R Benveniste, J Davies
Oct 15, 1973·Biochemical and Biophysical Research Communications·Y M Kupersztoch, D R Helinski
Sep 1, 1974·Proceedings of the National Academy of Sciences of the United States of America·V HershfieldD R Helinski
Apr 1, 1969·Proceedings of the National Academy of Sciences of the United States of America·D B Clewell, D R Helinski
Oct 14, 1970·Journal of Molecular Biology·M Mandel, A Higa
Jun 4, 1971·Biochemical and Biophysical Research Communications·J S Erickson, C K Mathews

Related Concepts

Alkalescens-Dispar Group
Deoxyribonuclease BamHI
Tetrahydrofolate Dehydrogenase
Mutagenesis Procedure

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