Biomaterial Database

Bactericidal effect of 5-azacytidine on Escherichia coli carrying EcoRII restriction-modification enzymes. 1982

S Friedman

5-Azacytidine was found to be bactericidal to Escherichia coli carrying plasmids specifying EcoRII restriction-modification systems, but not to the same strains lacking these plasmids. Of other base analogs tested, only 5(beta-D-ribofuranosyl)isocytidine had similar, although weaker, effects. Plasmids that had lost the EcoRII restriction-modification system did not confer sensitivity to 5-azacytidine. Mutants defective in the restriction function remained sensitive to the toxic effects of the drug; however, a mutant defective in the modification function lost most of the sensitivity to 5-azacytidine. For the bactericidal effect to be seen, the cells had to be growing; cells in the stationary phase of growth were not killed by the drug. The drug inhibited the methylase enzyme, and an inhibitor of the enzyme could be detected in vitro in extracts of cells that had been treated with 5-azacytidine. This nalidixic acid inhibited its formation. Coumermycin but not nalidixic acid antagonized the bactericidal effect of the drug; however, coumermycin was more effective in preventing the inhibition of the methylase by 5-azacytidine than was nalidixic acid.

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
D002470	Cell Survival	The span of viability of a cell characterized by the capacity to perform certain functions such as metabolism, growth, reproduction, some form of responsiveness, and adaptability.	Cell Viability,Cell Viabilities,Survival, Cell,Viabilities, Cell,Viability, Cell
D003090	Coliphages	Viruses whose host is Escherichia coli.	Escherichia coli Phages,Coliphage,Escherichia coli Phage,Phage, Escherichia coli,Phages, Escherichia coli
D004262	DNA Restriction Enzymes	Enzymes that are part of the restriction-modification systems. They catalyze the endonucleolytic cleavage of DNA sequences which lack the species-specific methylation pattern in the host cell's DNA. Cleavage yields random or specific double-stranded fragments with terminal 5'-phosphates. The function of restriction enzymes is to destroy any foreign DNA that invades the host cell. Most have been studied in bacterial systems, but a few have been found in eukaryotic organisms. They are also used as tools for the systematic dissection and mapping of chromosomes, in the determination of base sequences of DNAs, and have made it possible to splice and recombine genes from one organism into the genome of another. EC 3.21.1.	Restriction Endonucleases,DNA Restriction Enzyme,Restriction Endonuclease,Endonuclease, Restriction,Endonucleases, Restriction,Enzymes, DNA Restriction,Restriction Enzyme, DNA,Restriction Enzymes, 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
D001374	Azacitidine	A pyrimidine analogue that inhibits DNA methyltransferase, impairing DNA methylation. It is also an antimetabolite of cytidine, incorporated primarily into RNA. Azacytidine has been used as an antineoplastic agent.	Azacytidine,5-Azacytidine,NSC-102816,Vidaza,5 Azacytidine,NSC 102816,NSC102816
D013045	Species Specificity	The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.	Species Specificities,Specificities, Species,Specificity, Species
D015252	Deoxyribonucleases, Type II Site-Specific	Enzyme systems containing a single subunit and requiring only magnesium for endonucleolytic activity. The corresponding modification methylases are separate enzymes. The systems recognize specific short DNA sequences and cleave either within, or at a short specific distance from, the recognition sequence to give specific double-stranded fragments with terminal 5'-phosphates. Enzymes from different microorganisms with the same specificity are called isoschizomers. EC 3.1.21.4.	DNA Restriction Enzymes, Type II,DNase, Site-Specific, Type II,Restriction Endonucleases, Type II,Type II Restriction Enzymes,DNase, Site Specific, Type II,Deoxyribonucleases, Type II, Site Specific,Deoxyribonucleases, Type II, Site-Specific,Site-Specific DNase, Type II,Type II Site Specific DNase,Type II Site Specific Deoxyribonucleases,Type II Site-Specific DNase,Type II Site-Specific Deoxyribonucleases,Deoxyribonucleases, Type II Site Specific,Site Specific DNase, Type II