Open AccessRad50 Is Not Essential for the Mre11-Dependent Repair of DNA Double-Strand Breaks in Halobacterium sp. Strain NRC-1
Author(s) -
Adrienne Kish,
Jocelyne DiRuggiero
Publication year - 2008
Publication title -
journal of bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.652
H-Index - 246
eISSN - 1067-8832
pISSN - 0021-9193
DOI - 10.1128/jb.00292-08
Subject(s) - biology , rad50 , strain (injury) , dna , dna repair , halobacterium , genetics , double strand , halobacteriaceae , microbiology and biotechnology , dna binding protein , bacteria , halobacterium salinarum , gene , halophile , anatomy , archaea , transcription factor
The genome of the halophilic archaeonHalobacterium sp. strain NRC-1 encodes homologs of the eukaryotic Mre11 and Rad50 proteins, which are involved in the recognition and end processing of DNA double-strand breaks in the homologous recombination repair pathway. We have analyzed the phenotype ofHalobacterium deletion mutants lackingmre11 and/orrad50 after exposure to UV-C radiation, an alkylating agent (N -methyl-N ′-nitro-N -nitrosoguanidine), and γ radiation, none of which resulted in a decrease in survival of the mutant strains compared to that of the background strain. However, a decreased rate of repair of DNA double-strand breaks in strains lacking themre11 gene was observed using pulsed-field gel electrophoresis. These observations led to the hypothesis that Mre11 is essential for the repair of DNA double-strand breaks inHalobacterium , whereas Rad50 is dispensable. This is the first identification of a Rad50-independent function for the Mre11 protein, and it represents a shift in theArchaea away from the eukaryotic model of homologous recombination repair of DNA double-strand breaks.