ssDNA-binding protein that contributes to the ionizing radiation resistance of D.deserti. 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 (Probable). In vitro, binds to the 3'-ends of single-stranded DNA, and probably protects them from nuclease degradation. Thus, DdrA is part of a DNA end-protection system that helps to preserve genome integrity following irradiation or desiccation. The truncated form (1-160) of DdrA forms heptameric rings that can assemble into a 3-ring structure. Induced to high levels following extreme ionizing radiation exposure. Also highly induced in response to desiccation stress (By similarity). The N-terminal domain (1-160) is sufficient to pilot the oligomerization process and to bind specifically single-stranded DNA, but is not functional in vivo. Belongs to the RAD52 family.