title: Novel mechanism of resistance to folate analogues: ribonucleoside diphosphate reductase deficiency in bacteriophage T4.
abstract: Some spontaneously occurring bacteriophage T4 mutants (far mutants) were able to form plaques in the presence of concentrations of folate analogues that completely inhibit plaque formation by wild-type phage T4. Some of these far mutants were shown to be ribonucleoside diphosphate (RDP) reductase (EC 1.17.4.1) deficient, and some independently isolated RDP reductase-deficient mutants (nrd mutants) were shown to be folate analogue resistant. The map positions of the RDP reductase-deficient far mutants were shown to be within the genes controlling the phage-induced RDP reductase activity.
mesh_terms: D002874:Chromosome Mapping; D003090:Coliphages / Q000187:drug effects / Q000201:enzymology*; D004352:Drug Resistance, Microbial; D005492:Folic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D009154:Mutation; D012262:Ribonucleoside Diphosphate Reductase / Q000378:metabolism*; D012264:Ribonucleotide Reductases / Q000378:metabolism*
chemical_list: D005492:Folic Acid; D012264:Ribonucleotide Reductases; D012262:Ribonucleoside Diphosphate Reductase