title: Altered dihydrofolate reductase in fol regulatroy mutants of Escherichia coli K12.
abstract: Three spontaneous fol regulatory mutants contain dihydrofolate reductase molecules which differ in physical properties from enzymes of their parent strains. The enzymes were purified over 100-fold by affinity chromatography and were shown to differ in vitro in thermolability and in affinity for trimethoprim, a competitive inhibitor of the enzyme. These results indicate that some fol regulatroy mutations occur in the structural gene for dihydrofolate reductase.
mesh_terms: D002846:Chromatography, Affinity; D004926:Escherichia coli / Q000201:enzymology*; D005796:Genes; D005809:Genes, Regulator; D008968:Molecular Conformation; D009154:Mutation; D013762:Tetrahydrofolate Dehydrogenase / Q000096:biosynthesis; D014295:Trimethoprim / Q000378:metabolism
chemical_list: D014295:Trimethoprim; D013762:Tetrahydrofolate Dehydrogenase