Sensitization of Escherichia coli C to gamma-radiation by 5-bromouracil incorporation. 1977

T Bonura, and K C Smith

Escherichia coli C cells, unifilarly substituted with 5-bromouracil (BrUra) were 2-25 times as sensitive as unsubstituted cells to killing by gamma-irradiation under aerobic conditions. The yield of DNA double-strand breaks in BrUra-substituted cells was increased by a factor only 1-55, suggesting that other lesions also contribute to cell-killing. Alkaline sucrose density gradient analysis of the 3H-thymine labelled DNA strand showed there was less repair of gamma-ray-induced single-strand breaks when BrUra was in the complementary strand. Since there are more of these unrepaired breaks than can be accounted for by BrUra-induced DNA double-strand breakage, some fraction of the lethal events in BrUra-substituted E. coli cells may be unrepaired DNA single-strand breaks.

UI MeSH Term Description Entries
D011836 Radiation Tolerance The ability of some cells or tissues to survive lethal doses of IONIZING RADIATION. Tolerance depends on the species, cell type, and physical and chemical variables, including RADIATION-PROTECTIVE AGENTS and RADIATION-SENSITIZING AGENTS. Radiation Sensitivity,Radiosensitivity,Sensitivity, Radiation,Tolerance, Radiation,Radiation Sensitivities,Radiation Tolerances,Radiosensitivities,Sensitivities, Radiation,Tolerances, Radiation
D011838 Radiation-Sensitizing Agents Drugs used to potentiate the effectiveness of radiation therapy in destroying unwanted cells. Radiation Sensitizer,Radiosensitizing Agent,Radiosensitizing Agents,Agents, Radiation-Sensitizing,Radiation Sensitizers,Radiation Sensitizing Agents,Radiation-Sensitizing Drugs,Radiation-Sensitizing Effect,Radiation-Sensitizing Effects,Radiosensitizing Drugs,Radiosensitizing Effect,Radiosensitizing Effects,Agent, Radiosensitizing,Agents, Radiation Sensitizing,Agents, Radiosensitizing,Drugs, Radiation-Sensitizing,Drugs, Radiosensitizing,Effect, Radiation-Sensitizing,Effect, Radiosensitizing,Effects, Radiation-Sensitizing,Effects, Radiosensitizing,Radiation Sensitizing Drugs,Radiation Sensitizing Effect,Radiation Sensitizing Effects,Sensitizer, Radiation,Sensitizers, Radiation,Sensitizing Agents, Radiation
D001976 Bromouracil 5-Bromo-2,4(1H,3H)-pyrimidinedione. Brominated derivative of uracil that acts as an antimetabolite, substituting for thymine in DNA. It is used mainly as an experimental mutagen, but its deoxyriboside (BROMODEOXYURIDINE) is used to treat neoplasms. 5-Bromouracil,Bromuracil,5 Bromouracil
D002499 Centrifugation, Density Gradient Separation of particles according to density by employing a gradient of varying densities. At equilibrium each particle settles in the gradient at a point equal to its density. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed) Centrifugations, Density Gradient,Density Gradient Centrifugation,Density Gradient Centrifugations,Gradient Centrifugation, Density,Gradient Centrifugations, Density
D004269 DNA, Bacterial Deoxyribonucleic acid that makes up the genetic material of bacteria. Bacterial DNA
D004277 DNA, Single-Stranded A single chain of deoxyribonucleotides that occurs in some bacteria and viruses. It usually exists as a covalently closed circle. Single-Stranded DNA,DNA, Single Stranded,Single Stranded 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
D005720 Gamma Rays Penetrating, high-energy electromagnetic radiation emitted from atomic nuclei during NUCLEAR DECAY. The range of wavelengths of emitted radiation is between 0.1 - 100 pm which overlaps the shorter, more energetic hard X-RAYS wavelengths. The distinction between gamma rays and X-rays is based on their radiation source. Gamma Wave,Gamma Radiation,Nuclear X-Rays,Radiation, Gamma,X-Rays, Nuclear,Gamma Radiations,Gamma Ray,Gamma Waves,Nuclear X Rays,Nuclear X-Ray,Ray, Gamma,Wave, Gamma,Waves, Gamma,X Rays, Nuclear,X-Ray, Nuclear

Related Publications

T Bonura, and K C Smith
January 1971, International journal of radiation biology and related studies in physics, chemistry, and medicine,
T Bonura, and K C Smith
January 1968, Molecular & general genetics : MGG,
Copied contents to your clipboard!