Repair of damage in double-stranded PHI X174 (RF) DNA due to radiation-induced water radicals

In order to investigate whether possible damage due to hydrated electrons is repaired by one of the various DNA repair systems and, in addition, whether any difference exists in the type of damage introduced by H or OH radicals, experiments were carried out in which the biological activity of the DNA was determined also with spheroplasts, prepared from Escherichia coli strains which are deficient in excision repair (uvrA- or uvrC-) or post-replication repair (recA-). From these experiments it can be concluded that the type of damage introduced by H radicals must be different from that introduced by OH radicals. No repair could be detected by any of the DNA repair systems investigated in the case of possible damage due to hydrated electrons. (author)