A Novel protein that recognizes DNA strand break

Narumi, Issei; Sato, Katsuya; Kikuchi, Masahiro

is characterized by its extraordinary resistance to the lethal and mutagenic effects of ionizing and ultraviolet irradiations and many other DNA-damaging agents. By analyzing a DNA repair-deficient mutant strain, we discovered that a novel protein participates in the extreme radiation resistance of . The protein (designated PprA for promoting prominent repair) can recognize DNA strand breaks. Further, PprA would protect irradiation-damaged DNA from exonuclease activity and consequent degradation and thereby ensure DNA repair processes could function. Beside DNA-binding ability, PprA can promote the activities of DNA ligase and RecA, suggesting that PprA functions as a DNA repair-promoting protein to potentiate the effectiveness of DNA repair. These properties enable PprA to use the widespread application and .