Experiments on the Filling of Daughter-Strand Gaps During Postreplication Repair
When Escherichia coli deficient in excision-repair replicate their DNA after UV irradiation, the newly synthesized strands contain gaps, presumed to be opposite pyrimidine dimers, which are rejoined during subsequent incubation (Rupp and Howard-Flanders, 1968), by a process believed to be recombinational in nature (Rupp et al., 1971). The detailed mechanism of postreplication repair is, however, far from clear. We have attempted to answer two somewhat different questions: (1) whether or not the daughter-strand gap persists because of the continued presence of the dimer on the opposite strand, and (2) which if any of the three DNA polymerases are required for filling of daughter-strand gaps.
KeywordsOpposite Strand Pyrimidine Dimer Restrictive Temperature Postreplication Repair Repair Replication
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