Fig. 3.
Working model for the repair of inter-strand DNA cross-links in bacteria. The UvrABC proteins were shown to incise on one side of a psoralen cross-link. This gapped substrate was processed by a RecA filament to generate a three-stranded intermediate. In a second round of incisions, UvrABC was shown to act on the psoralen-cross-linked-excised oligonucleotide. Gap filling by DNA polymerase I and ligation complete the repair process. This incision/recombination/incision model is based on a previous model of Cole [38]. From Ref. [76] with permission.