Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: EC:1.5.1.3 (
dihydrofolate reductase
)
5,819
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Two clones from the Clarke-Carbon Escherichia coli colony bank were resistant to inhibition by trimethoprim, a potent inhibitor of
dihydrofolate reductase
. Both clones had elevated levels of
dihydrofolate reductase
. Furthermore, trimethoprim resistance and elevated enzyme levels were associated with ColE1 plasmids that carried DNA from the
trkC
ksgA pdxA region of the E. coli chromosome. Plasmid pLC1437a was shown by two criteria to carry the structural gene for
dihydrofolate reductase
: 1) A partial diploid containing plasmid pLC1437a produced a kinetically-recognizable
dihydrofolate reductase
that was not present in the parent haploid strain. 2) Plasmid pLC1437a coded for
dihydrofolate reductase
in vitro. A 1,000 base pair fragment of plasmid pLC1437a containing fol was used as a probe to measure fol mRNA in a mutant strain isolated by Sheldon and Brenner (Molec. gen. Genet. 147, 91-97, 1976). The mutation in this strain, which results in constitutively-high levels of
dihydrofolate reductase
and in the inability of the strain to grow at 42 degrees C, is cis dominant (Sheldon and Brenner, 1976). The results of kinetic hybridization and pulse-labeling experiments indicated that the regulatory mutant produced elevated levels of
dihydrofolate reductase
in response to an increased rate of synthesis of fol mRNA.
...
PMID:Regulation of dihydrofolate reductase synthesis in Escherichia coli. 39 Mar 4
