title: Mapping of the resistance genes of the R plasmid NR1.
abstract: The drug resistance genes on the r-determinants component of the composite R plasmid NR1 were mapped on the EcoRI restriction endonuclease fragments of the R plasmid by cloning the fragments using the plasmid RSF2124 as a vector. The sulfonamide (Su) and streptomycin/spectinomycin (Sm/Sp) resistance genes are located on EcoRI fragment G of NR1. The expression of resistance to mercuric ions (Mer) requires both EcoRI fragment H and I of NR1. The expression of chloramphenicol (Cm) and fusidic acid (Fus) resistance requires EcoRI fragments A and J of NR1. The kan fragment of the related R plasmid R6-5 can substitute for Eco RI fragment J of NR1 in the expression of Cm and Fus resistance. The structural genes for Cm and Fus resistance appear to be a part of an operon whose expression is controlled by the same promoter.
mesh_terms: D002701:Chloramphenicol / Q000494:pharmacology; D004926:Escherichia coli / Q000235:genetics; D005672:Fusidic Acid / Q000494:pharmacology; D005796:Genes; D008040:Genetic Linkage; D008628:Mercury / Q000494:pharmacology; D011815:R Factors; D000198:Spectinomycin / Q000494:pharmacology; D013307:Streptomycin / Q000494:pharmacology; D013449:Sulfonamides / Q000494:pharmacology; D013752:Tetracycline / Q000494:pharmacology
chemical_list: D013449:Sulfonamides; D005672:Fusidic Acid; D002701:Chloramphenicol; D000198:Spectinomycin; D013752:Tetracycline; D008628:Mercury; D013307:Streptomycin