Protein expression in Escherichia coli minicells containing recombinant plasmids specifying trimethoprim-resistant dihydrofolate reductases.
AUTOR(ES)
Fling, M E
RESUMO
Deoxyribonucleic acid fragments containing the structural genes for several trimethoprim-resistant dihydrofolate reductases from naturally occurring plasmids were inserted into small cloning vehicles. The genetic expression of these hybrid plasmids was studied in purified Escherichia coli minicells. The type I dihydrofolate reductase, encoded by plasmid R483 and residing within transposon 7 (Tn7), had a subunit molecular weight of 18,000. The type II dihydrofolate reductase, specified by plasmid R67, had a subunit molecular weight of 9,000. These two enzymes were antigenically distinct in that anti-type II dihydrofolate reductase (R67) antibody did not cross-react with the type I (R483) protein. The trimethoprim-resistant reductase specified by plasmid R388 had a subunit molecular weight of about 10,500 and was immunologically related to the type II (R67) enzyme. A 9,000 subunit of the dihydrofolate encoded by the transposition element Tn402 was also antigenically related to the R67 reductase.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=293688Documentos Relacionados
- Identification of the type I trimethoprim-resistant dihydrofolate reductase specified by the Escherichia coli R-plasmid R483: comparison with procaryotic and eucaryotic dihydrofolate reductases.
- Isolation and characterization of dihydrofolate reductase from trimethoprim-susceptible and trimethoprim-resistant Pseudomonas cepacia.
- Mutations in the dihydrofolate reductase gene of trimethoprim-resistant isolates of Streptococcus pneumoniae.
- Multiple Mutations Modulate the Function of Dihydrofolate Reductase in Trimethoprim-Resistant Streptococcus pneumoniae
- Characterization of Dihydrofolate Reductase Genes from Trimethoprim-Susceptible and Trimethoprim-Resistant Strains of Enterococcus faecalis