title: New nalidixic acid resistance mutations related to deoxyribonucleic acid gyrase activity.
abstract: In Escherichia coli K-12 mutants which had a new nalidixic acid resistance mutation at about 82 min on the chromosome map, cell growth was resistant to or hypersusceptible to nalidixic acid, oxolinic acid, piromidic acid, pipemidic acid, and novobiocin. Deoxyribonucleic acid gyrase activity as tested by supercoiling of lambda phage deoxyribonucleic acid inside the mutants was similarly resistant or hypersusceptible to the compounds. The drug concentrations required for gyrase inhibition were much higher than those for cell growth inhibition but similar to those for inhibition of lambda phage multiplication. Transduction analysis with lambda phages carrying the chromosomal fragment of the tnaA-gyrB region suggested that one of the mutations, nal-31, was located on the gyrB gene.
mesh_terms: D010582:Bacteriophage lambda / Q000254:growth & development; D004250:DNA Topoisomerases, Type II / Q000378:metabolism*; D004352:Drug Resistance, Microbial; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics; D005798:Genes, Bacterial; D009154:Mutation; D009268:Nalidixic Acid / Q000494:pharmacology*; D014161:Transduction, Genetic
chemical_list: D009268:Nalidixic Acid; D004250:DNA Topoisomerases, Type II