title: Isolation and characterisation of a strain carrying a conditional lethal mutation in the cou gene of Escherichia coli K12.
abstract: A strain which carries a mutation conferring clorobiocin resistance and temperature sensitivity for growth was isolated from Escherichia coli K12. Genetic mapping and the molecular weight of the gene product suggest that the mutation is in the cou gene, specifying a sub-unit of DNA gyrase. Nuclear organisation and segregation and placement of septa are grossly abnormal in the mutant at 42 degrees C. RNA synthesis and initiation of DNA replication are also affected at the restrictive temperature but the rate of DNA chain elongation continues almost undisturbed.
mesh_terms: D002874:Chromosome Mapping; D002876:Chromosomes, Bacterial / Q000648:ultrastructure; D004261:DNA Replication; D004250:DNA Topoisomerases, Type II / Q000235:genetics; D004269:DNA, Bacterial / Q000096:biosynthesis; D004352:Drug Resistance, Microbial; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics*; D005804:Genes, Lethal; D009154:Mutation; D009675:Novobiocin / Q000031:analogs & derivatives / Q000494:pharmacology; D012329:RNA, Bacterial / Q000096:biosynthesis; D013696:Temperature; D014161:Transduction, Genetic
chemical_list: D004269:DNA, Bacterial; D012329:RNA, Bacterial; D009675:Novobiocin; C006260:clorobiocin; D004250:DNA Topoisomerases, Type II