Naslov
RecA protein assures fidelity of DNA repair and genome stability in Deinococcus radiodurans

Autori
Repar, Jelena ; Cvjetan, Svjetlana ; Slade, Dea ; Radman, Miroslav ; Zahradka, Davor ; Zahradka, Ksenija

Izvornik
DNA repair (1568-7864) 9 (2010), 11; 1151-1161

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Deinococcus radiodurans ; DNA repair ; gamma-radiation ; genome rearrangements ; RecA protein

Sažetak
Deinococcus radiodurans is one of the most radiation-resistant organisms known. It can repair hundreds of radiation-induced double-strand DNA breaks without loss of viability. Genome reassembly in heavily irradiated D. radiodurans is considered to be an error-free process since no genome rearrangements were detected after post-irradiation repair. Here, we describe for the first time conditions that frequently cause erroneous chromosomal assemblies. Gross chromosomal rearrangements have been detected in recA mutant cells that survived exposure to 5 kGy gamma-radiation. The recA mutants are prone also to spontaneous DNA rearrangements during normal exponential growth. Some insertion sequences have been identified as dispersed genomic homology blocks that can mediate DNA rearrangements. Whereas the wild-type D. radiodurans appears to repair accurately its genome shattered by 5 kGy gamma-radiation, extremely high gamma-doses, e.g., 25 kGy, produce frequent genome rearrangements among survivors. Our results show that the RecA protein is quintessential for the fidelity of repair of both spontaneous and gamma-radiation-induced DNA breaks and, consequently, for genome stability in D. radiodurans. The mechanisms of decreased genome stability in the absence of RecA are discussed.

Izvorni jezik
Engleski

Znanstvena područja
Biologija

POVEZANOST RADA