title: Effect of cysteine modification on dihydrofolate reductase from a methotrexate-resistant strain of Escherichia coli B. Identification of modified residues.
mesh_terms: D002614:Chelating Agents / Q000494:pharmacology; D002942:Circular Dichroism; D003300:Copper / Q000494:pharmacology; D003545:Cysteine; D004228:Dithionitrobenzoic Acid / Q000494:pharmacology; D004352:Drug Resistance, Microbial; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology*; D008623:Mercaptoethanol / Q000494:pharmacology; D008727:Methotrexate / Q000494:pharmacology*; D010662:Phenylmercuric Acetate / Q000494:pharmacology; D011487:Protein Conformation; D013762:Tetrahydrofolate Dehydrogenase / Q000378:metabolism*
chemical_list: D002614:Chelating Agents; D008623:Mercaptoethanol; D003300:Copper; D004228:Dithionitrobenzoic Acid; D013762:Tetrahydrofolate Dehydrogenase; D003545:Cysteine; D010662:Phenylmercuric Acetate; D008727:Methotrexate