PprA; A Novel protein from that stimulates DNA ligation

Narumi, Issei; Sato, Katsuya; Cui, S.*; Funayama, Tomoo; Kitayama, Shigeru; Watanabe, Hiroshi*

The extraordinary radiation resistance of results from the efficient capacity of the bacterium to repair DNA double-strand breaks. By analyzing the DNA damage repair-deficient mutant, KH311, a unique radiation-inducible gene (designated ) responsible for loss of radiation resistance was identified. Investigations in vitro showed that the gene product of (PprA) preferentially bound to double-stranded DNA carrying strand breaks, inhibited exonuclease III activity, and stimulated the DNA end-joining reaction catalyzed by ATP-dependent and NAD-dependent DNA ligases. These results suggest that has a radiation-induced nonhomologous end-joining repair mechanism in which PprA plays a critical role.