Isolation and expression of the Pneumocystis carinii dihydrofolate reductase gene

Proc Natl Acad Sci U S A. 1989 Nov;86(22):8625-9. doi: 10.1073/pnas.86.22.8625.

Abstract

Pneumocystis carinii dihydrofolate reductase (DHFR; 5,6,7,8-tetrahydrofolate: NADP+ oxidoreductase, EC 1.5.1.3) cDNA sequences have been isolated by their ability to confer trimethoprim resistance to Escherichia coli. Consistent with the recent conclusion that P. carinii is a member of the Fungi, sequence analysis and chromosomal localization show that DHFR is neither physically nor genetically linked to thymidylate synthase. Expression of recombinant P. carinii DHFR in heterologous hosts provides an abundant source of the enzyme that may form a basis for the development of new therapies for this enigmatic pathogen. Studies with the recombinant enzyme show that trimethoprim is a very poor inhibitor of P. carinii DHFR and, in fact, is a more potent inhibitor of human DHFR.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Cloning, Molecular
  • DNA, Bacterial / genetics
  • DNA, Bacterial / isolation & purification
  • Escherichia coli / genetics
  • Gene Expression
  • Gene Library
  • Genes, Bacterial*
  • Humans
  • Molecular Sequence Data
  • Oligonucleotide Probes
  • Plasmids
  • Pneumocystis / enzymology
  • Pneumocystis / genetics*
  • Sequence Homology, Nucleic Acid
  • Tetrahydrofolate Dehydrogenase / genetics*

Substances

  • DNA, Bacterial
  • Oligonucleotide Probes
  • Tetrahydrofolate Dehydrogenase

Associated data

  • GENBANK/M26495
  • GENBANK/M26496