title: Hyperproduction mutation in the dihydrofolate reductase gene of Diplococcus pneumoniae: some effects on synthesis correlate with the presence of a modified enzyme form.
mesh_terms: D002850:Chromatography, Gel; D004352:Drug Resistance, Microbial; D005796:Genes; D005827:Genetics, Microbial; D007700:Kinetics; D008727:Methotrexate / Q000494:pharmacology; D008970:Molecular Weight; D009154:Mutation; D011995:Recombination, Genetic; D013296:Streptococcus pneumoniae / Q000201:enzymology*; D013762:Tetrahydrofolate Dehydrogenase / Q000096:biosynthesis*; D014170:Transformation, Genetic
chemical_list: D013762:Tetrahydrofolate Dehydrogenase; D008727:Methotrexate