Genetic Analysis of RadB, a Paralogue of the Archaeal Rad51/RecA Homologue, RadA

摘要: The integrity of all genomes is under constant threat, with DNA double strand breaks being particularly dangerous. Double can be repaired by homologous recombination, a process catalysed recombinase proteins the RecA family. The archaeal recombinase, RadA, to eukaryotic and bacterial Rad51/RecA. Euryarchaea encode an additional Rad51/RecA homologue, RadB. RadB shares homology core domain RadA has been shown bind both single stranded DNA, binds ATP possesses very weak ATPase activity. However, does not catalyse exchange. interact Holliday junction resolvase (Hjc) polymerase (PolD), suggesting role in recombination. In this study, radB was deleted from halophilic archaeon, Haloferax volcanii. 'delta' strains were slow growing, sensitive mitomycin C UV irradiation, deficient for crossover non-crossover Deletion radA results similar phenotypic characteristics, complete abrogation Strains are equally defective as strains, demonstrating that epistatic A suppressor isolated identified mutation polymerisation (RadA-A196V). radA-A196V suppresses growth, recombination defects associated radB, well sensitivity phenotypes. On account nature suppressor, observed interaction between RadB, relationship mediator protein proposed. Finally, hjc. hjc exhibit no sensitivity. This suggests another, yet unidentified, encoded