ssDNA-binding protein that contributes to the ionizing radiation resistance of D.radiodurans. Plays a role in DNA repair and genome reconstitution, in a RecA-independent process, since DdrA is essential for recovery from severe genomic fragmentation as a result of exposure to severe levels of ionizing radiation in an environment lacking nutrients. In vitro, binds to the 3'-ends of single-stranded DNA, protecting them from nuclease degradation. Thus, DdrA is part of a DNA end-protection system that helps to preserve genome integrity following irradiation or desiccation. Does not display DNA strand annealing activity, unlike eukaryotic Rad52 protein homologs. Homooligomer composed of 8 to 10 subunits; probably arranged in a ring-structure. Induced to high levels following extreme ionizing radiation exposure. Also highly induced in response to desiccation stress. Cells lacking this gene show a normal growth rate, do not exhibit a decrease in the efficiency of natural transformation, but display a reduced capacity to survive ionizing radiation when exposed at doses superior to 2.5 kGy and exhibit increased sensitivity to mitomycin C. Belongs to the RAD52 family.