A Novel protein that recognizes DNA strand break

DNA鎖切断を認識する新規タンパク質

鳴海 一成; 佐藤 勝也; 菊地 正博

Narumi, Issei; Sato, Katsuya; Kikuchi, Masahiro

放射線抵抗性細菌デイノコッカス・ラジオデュランスの放射線感受性変異株を解析し、放射線耐性に重要な新規タンパク質(PprA)を発見した。PprAはDNA鎖切断を認識して結合し、ヌクレオチド分解酵素からDNA切断末端を保護し、効率的な修復をもたらす。またPprAは、DNAリガーゼによるDNA 鎖結合反応とRecAタンパク質を介するDNA組み換え修復反応を促進する活性を有する。このような性質により、PprAの広範囲での応用が期待される。

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 .