Abstract
Investigation of the effect of photoreactivation, excision, and recombination repair, individually and in combination, on the survival of ultraviolet-irradiated Escherichia coli K-12 mutants has led to a possible explanation of the loss of photoreactivability and of the complex changes in viability observed during liquid-holding. It is suggested that at higher ultraviolet light doses the excision repair mechanism becomes saturated due to overlapping of excised regions on opposite strands of the deoxyribonucleic acid helix. The results also provide support for the existing hypothesis that states that the shape of shouldered survival curves of ultraviolet-irradiated bacteria can be described in terms of the probability of occurrance of overlapping excised regions. Using the data obtained with repair-deficient mutants with closely related genetic makeup, we present a mathematical model that accurately predicts the shape of the observed survival curves and provides an estimate of the number of nucleotides in each fragment of deoxyribonucleic acid removed by the excision repair mechanism.
Full text
PDF








Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- ADELBERG E. A., BURNS S. N. Genetic variation in the sex factor of Escherichia coli. J Bacteriol. 1960 Mar;79:321–330. doi: 10.1128/jb.79.3.321-330.1960. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Anderson E. H. Growth Requirements of Virus-Resistant Mutants of Escherichia Coli Strain "B". Proc Natl Acad Sci U S A. 1946 May;32(5):120–128. doi: 10.1073/pnas.32.5.120. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Cooper P. K., Hanawalt P. C. Heterogeneity of patch size in repair replicated DNA in Escherichia coli. J Mol Biol. 1972 Jun 14;67(1):1–10. doi: 10.1016/0022-2836(72)90381-6. [DOI] [PubMed] [Google Scholar]
- Ganesan A. K., Smith K. C. Dark recovery processes in Escherichia coli irradiated with ultraviolet light. I. Effect of rec mutations on liquid holding recovery. J Bacteriol. 1968 Aug;96(2):365–373. doi: 10.1128/jb.96.2.365-373.1968. [DOI] [PMC free article] [PubMed] [Google Scholar]
- HOWARD-FLANDERS P., BOYCE R. P., SIMSON E., THERIOT L. A genetic locus in E. coli K12 that controls the reactivation of UV-photoproducts associated with thymine in DNA. Proc Natl Acad Sci U S A. 1962 Dec 15;48:2109–2115. doi: 10.1073/pnas.48.12.2109. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Harm W. Dark repair of photorepairable UV lesions in Escherichia coli. Mutat Res. 1968 Jul-Aug;6(1):25–35. doi: 10.1016/0027-5107(68)90100-0. [DOI] [PubMed] [Google Scholar]
- Harm W. Effects of dose fractionation on ultraviolet survival of Escherichia coli. Photochem Photobiol. 1968 Jan;7(1):73–86. doi: 10.1111/j.1751-1097.1968.tb05831.x. [DOI] [PubMed] [Google Scholar]
- Haynes R. H. The interpretation of microbial inactivation and recovery phenomena. Radiat Res. 1966;(Suppl):1–29. [PubMed] [Google Scholar]
- Howard-Flanders P., Boyce R. P. DNA repair and genetic recombination: studies on mutants of Escherichia coli defective in these processes. Radiat Res. 1966;(Suppl):156+–156+. [PubMed] [Google Scholar]
- Howard-Flanders P., Theriot L. Mutants of Escherichia coli K-12 defective in DNA repair and in genetic recombination. Genetics. 1966 Jun;53(6):1137–1150. doi: 10.1093/genetics/53.6.1137. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kelner A. PHOTOREACTIVATION OF ULTRAVIOLET-IRRADIATED ESCHERICHIA COLI, WITH SPECIAL REFERENCE TO THE DOSE-REDUCTION PRINCIPLE AND TO ULTRAVIOLET-INDUCED MUTATION. J Bacteriol. 1949 Oct;58(4):511–522. doi: 10.1128/jb.58.4.511-522.1949. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ley R. D., Setlow R. B. Repair replication in Escherichia coli as measured by the photolysis of bromodeoxyuridine. Biophys J. 1972 Apr;12(4):420–431. doi: 10.1016/S0006-3495(72)86094-6. [DOI] [PMC free article] [PubMed] [Google Scholar]
- SETLOW R. B., CARRIER W. L. THE DISAPPEARANCE OF THYMINE DIMERS FROM DNA: AN ERROR-CORRECTING MECHANISM. Proc Natl Acad Sci U S A. 1964 Feb;51:226–231. doi: 10.1073/pnas.51.2.226. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tyrrell R. M., Moss S. H., Davies D. J. The variation in UV sensitivity of four K12 strains of Escherichia coli as a function of their stage of growth. Mutat Res. 1972 Sep;16(7):1–12. doi: 10.1016/0027-5107(72)90058-9. [DOI] [PubMed] [Google Scholar]
- Tyrrell R. M., Moss S. H., Davies D. J. The variation in photoreactivating enzyme activity as a function of the stage of growth of three K12 strains of Escherichia coli. Mutat Res. 1972 Dec;16(4):345–352. doi: 10.1016/0027-5107(72)90202-3. [DOI] [PubMed] [Google Scholar]