dsDNA-binding protein that contributes to the ionizing radiation resistance of D.radiodurans. Plays a role in DNA repair and genome reconstitution, and is necessary for recovery from severe genomic fragmentation as a result of exposure to severe levels of ionizing radiation. In vitro, binds to double-stranded DNA carrying strand breaks and stimulates the DNA end-joining reaction catalyzed by DNA ligases. Thus, PprA plays a critical role in a non-homologous end-joining (NHEJ) pathway for the repair of radiation-induced DNA double-strands breaks. Cannot bind to dsDNA without strand breaks or single-stranded DNA. Phosphorylation increases DNA binding affinity. Induced to high levels following extreme ionizing radiation exposure. Also highly induced in response to desiccation stress. Phosphorylated by RqkA in vitro. Phosphorylated primarily at Thr-88, and to a little extent at Ser-128 and Thr-160. Cells lacking this gene show a reduced growth rate, do not exhibit a decrease in the efficiency of natural transformation, but are much more sensitive to ionizing radiation than the wild-type strain. The PprA protein combined with an immunofluorescence technique can be used to visualize radiation-induced DNA strand breaks in mammalian cultured cells, allowing the evaluation of DNA damage responses. This detection method could also be applicable to genotoxic tests in the environmental and pharmaceutical fields. Truncated N-terminus.