Maintenance of DNA and Repair of Apurinic Sites
Escherichia coli cells contain an enzyme which hydrolyzes a phosphodiester bond near each apurinic site in double-stranded DNA. This endonuclease is specific for apurinic sites; it has no effect on normal DNA, and its action on alkylated DNA is restricted to apurinic sites. In vitro incubation with the endonuclease for apurinic sites, DNA polymerase I, and ligase permits repair of DNA containing apurinic sites. The endonuclease for apurinic sites might thus play a role in cell survival after a treatment with alkylating agents; as DNA spontaneously loses purines, the enzyme might also play a role in the maintenance of a normal DNA in every cell. Indeed, an endonuclease for apurinic sites has been found not only in bacteria but also in animal and plant cells; it is very active in thermophilic bacteria.
KeywordsSedimentation Velocity Sucrose Gradient Thermophilic Bacterium Phosphodiester Bond Sedimentation Profile
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- Friedberg, E. C., Hadi, S. M. and Goldthwait, D. A. (1969). J. Biol. Chem. 244, 5879. Gillespie, C. J., Gislason, G. S., Dugle, D. L. and Chapman, J. D. (1972). Radiat. Res. 21, 272.Google Scholar
- Paquette, Y., Crine, P. and Verly, W. G. (1972). Can. J. Biochem. 50, 1199.Google Scholar
- Tamm, C., Shapiro, H. S., Lipshitz, R. and Chargaff, E. (1953). J. Biol. Chem. 203,673. Verly, W. G., Gossard, F. and Crine, P. (1974). Proc. Nat. Acad. Sci. U.S.A. 71,2273. Verly, W. G. and Paquette, Y. (1970). Can. Fed. Biol. Soc., 685.Google Scholar
- Verly, W. G. and Paquette, Y. (1972b). Fed. Proc. 31(2),918 (abstr. 4001).Google Scholar
- Verly, W. G., Paquette, Y., Tremblay, C. and Thibodeau, L. (1972). Can. Fed. Biol. Soc., 673.Google Scholar