Double-strand breaks from single photochemical events in DNA containing 5-bromouracil. [Escherichia coli; uv radiation]

Journal Article · Fri Dec 01 04:00:00 EST 1978 · Biophys. J.; (United States)

DOI:https://doi.org/10.1016/S0006-3495(78)85410-1· OSTI ID:6469972

Krasin, F; Hutchinson, F

Ultraviolet irradiation of Escherichia coli cells with a low level of 5-bromouracil incorporated produces DNA double-strand breaks by single photochemical events, one such break per 100 single-strand breaks, the latter assayed in alkali-denatured DNA. About 2.5 to 4 double-strand breaks are produced per lethal hit, compared with about 6 double-strand breaks per lethal hit induced by gamma rays. These results are consistent with the hypothesis that an unrepaired DNA double-strand break is a major lethal event in both cases. The increase in sensitivity to ultraviolet (measured by colony-forming ability) seems linear in the number of bromouracils incorporated (0 to 20% of the thymines), and the linear relationship is much the same for incorporation in one or in both strands of the DNA double helix.

• Research Organization: Yale Univ., New Haven, CT
• OSTI ID: 6469972
• Journal Information: Biophys. J.; (United States), Journal Name: Biophys. J.; (United States) Vol. 24:3; ISSN BIOJA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400500 -- Photochemistry
560112* -- Radiation Effects on Biochemicals-- In Microorganisms-- (-1987)
560131 -- Radiation Effects on Microorganisms-- Basic Studies-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANTIMETABOLITES
ANTIMITOTIC DRUGS
AZINES
BACTERIA
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BROMOURACILS
CHEMICAL REACTIONS
COMPARATIVE EVALUATIONS
DNA
DRUGS
ELECTROMAGNETIC RADIATION
ESCHERICHIA COLI
GAMMA RADIATION
HETEROCYCLIC COMPOUNDS
HYDROXY COMPOUNDS
IONIZING RADIATIONS
IRRADIATION
MICROORGANISMS
NUCLEIC ACIDS
ORGANIC BROMINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PYRIMIDINES
RADIATION EFFECTS
RADIATIONS
RADIOINDUCTION
RADIOSENSITIVITY EFFECTS
STRAND BREAKS
ULTRAVIOLET RADIATION
URACILS