Biomaterial Database

Molecular cloning of a chromosomal DNA region encompassing the dihydrofolate reductase gene of Streptococcus pneumoniae. 1993

M T Pérez-Ureña, and M Espinosa

Center for Biological Investigations, Madrid, Spain.

Natural competence of Streptococcus pneumoniae was used to locate and enrich DNA restriction fragments, biologically active for transformation of thymidine-deficient to thymidine-proficient cells. Mutations in the dihydrofolate reductase gene are accompanied by resistance to the drug trimethoprim (Tp). A 6.5-kb region of the pneumococcal chromosome encompassing the dihydrofolate reductase gene has been cloned in plasmid pLS1. Escherichia coli mutants, resistant to Tp, became fully sensitive to the drug when they harbored the recombinant plasmid. The pneumococcal dfrA mutation has been mapped within a 500-bp DNA region.

UI	MeSH Term	Description	Entries
D010957	Plasmids	Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS.	Episomes,Episome,Plasmid
D002874	Chromosome Mapping	Any method used for determining the location of and relative distances between genes on a chromosome.	Gene Mapping,Linkage Mapping,Genome Mapping,Chromosome Mappings,Gene Mappings,Genome Mappings,Linkage Mappings,Mapping, Chromosome,Mapping, Gene,Mapping, Genome,Mapping, Linkage,Mappings, Chromosome,Mappings, Gene,Mappings, Genome,Mappings, Linkage
D002876	Chromosomes, Bacterial	Structures within the nucleus of bacterial cells consisting of or containing DNA, which carry genetic information essential to the cell.	Bacterial Chromosome,Bacterial Chromosomes,Chromosome, Bacterial
D003001	Cloning, Molecular	The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.	Molecular Cloning
D004269	DNA, Bacterial	Deoxyribonucleic acid that makes up the genetic material of bacteria.	Bacterial DNA
D004926	Escherichia coli	A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.	Alkalescens-Dispar Group,Bacillus coli,Bacterium coli,Bacterium coli commune,Diffusely Adherent Escherichia coli,E coli,EAggEC,Enteroaggregative Escherichia coli,Enterococcus coli,Diffusely Adherent E. coli,Enteroaggregative E. coli,Enteroinvasive E. coli,Enteroinvasive Escherichia coli
D005798	Genes, Bacterial	The functional hereditary units of BACTERIA.	Bacterial Gene,Bacterial Genes,Gene, Bacterial
D005816	Genetic Complementation Test	A test used to determine whether or not complementation (compensation in the form of dominance) will occur in a cell with a given mutant phenotype when another mutant genome, encoding the same mutant phenotype, is introduced into that cell.	Allelism Test,Cis Test,Cis-Trans Test,Complementation Test,Trans Test,Allelism Tests,Cis Tests,Cis Trans Test,Cis-Trans Tests,Complementation Test, Genetic,Complementation Tests,Complementation Tests, Genetic,Genetic Complementation Tests,Trans Tests
D013296	Streptococcus pneumoniae	A gram-positive organism found in the upper respiratory tract, inflammatory exudates, and various body fluids of normal and/or diseased humans and, rarely, domestic animals.	Diplococcus pneumoniae,Pneumococcus
D013762	Tetrahydrofolate Dehydrogenase	An enzyme of the oxidoreductase class that catalyzes the reaction 7,8-dihyrofolate and NADPH to yield 5,6,7,8-tetrahydrofolate and NADPH+, producing reduced folate for amino acid metabolism, purine ring synthesis, and the formation of deoxythymidine monophosphate. Methotrexate and other folic acid antagonists used as chemotherapeutic drugs act by inhibiting this enzyme. (Dorland, 27th ed) EC 1.5.1.3.	Dihydrofolate Dehydrogenase,Dihydrofolate Reductase,Folic Acid Reductase,Acid Reductase, Folic,Dehydrogenase, Dihydrofolate,Dehydrogenase, Tetrahydrofolate,Reductase, Dihydrofolate,Reductase, Folic Acid