title: Characterization of plasmid pAZ1 and the type III dihydrofolate reductase gene.
abstract: The plasmid pAZ1, which determines trimethoprim and sulfonamide resistance, was characterized by restriction endonuclease mapping. The restriction map was identical to that of the incQ plasmid RSF1010 over a 5.1-kbp region. The type III dihydrofolate reductase gene was cloned, and the DNA sequence was determined. The predicted protein had 162 amino acid residues, and it was more closely related to the gram-negative bacterial chromosomal dihydrofolate reductases than to other plasmid or vertebrate dihydrofolate reductases. Sequence identity was 51% with the Escherichia coli enzyme and 44% with the Neisseria gonorrhoeae enzyme.
authors.affiliation: Wellcome Research Laboratories, Research Triangle Park, North Carolina 27709.
authors.forename: M E
authors.initials: ME
authors.lastname: Fling
authors.forename: J
authors.initials: J
authors.lastname: Kope
authors.forename: C
authors.initials: C
authors.lastname: Richards
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D004262:DNA Restriction Enzymes; D004352:Drug Resistance, Microbial; D004926:Escherichia coli / Q000235:genetics; D005796:Genes; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D011815:R Factors; D012486:Salmonella typhimurium / Q000201:enzymology / Q000235:genetics*; D013449:Sulfonamides / Q000494:pharmacology; D013762:Tetrahydrofolate Dehydrogenase / Q000235:genetics*; D014295:Trimethoprim / Q000494:pharmacology
chemical_list: D013449:Sulfonamides; D014295:Trimethoprim; D013762:Tetrahydrofolate Dehydrogenase; D004262:DNA Restriction Enzymes