Conservation of eukaryotic DNA repair mechanisms.

PURPOSE: To discuss the evolutionary conservation of different DNA repair processes. The proteins that carry out base excision repair show a varying degree of structural conservation, but a high level of functional complementation between species, as might be expected for a sequential pathway. In nucleotide excision repair there is a high degree of structural conservation, but few examples of functional complementation because the process involves multiprotein complexes. Repair by homologous recombination involves proteins that are highly conserved structurally. The process of repair of DNA breaks by non-homologous end-joining is conserved in eukaryotes, but the level of sequence identity of several of the proteins is fairly low and some components involved in man do not appear to have sequence homologues in yeast.

CONCLUSIONS: All DNA repair processes are highly conserved. The degree of structural and functional conservation varies between the different processes.