title: Increased dihydrofolate reductase synthess in Diplococcus pneumoniae following translatable alteration of the structural gene. I. Genotype derivation and recombinational analyses.
mesh_terms: D002874:Chromosome Mapping; D004269:DNA, Bacterial; D004352:Drug Resistance, Microbial; D005796:Genes; D008727:Methotrexate / Q000494:pharmacology; D009154:Mutation / Q000187:drug effects / Q000528:radiation effects; D011995:Recombination, Genetic; D013296:Streptococcus pneumoniae / Q000201:enzymology*; D013762:Tetrahydrofolate Dehydrogenase / Q000096:biosynthesis*; D014170:Transformation, Genetic
chemical_list: D004269:DNA, Bacterial; D013762:Tetrahydrofolate Dehydrogenase; D008727:Methotrexate