D. radiodurans DR0199 protein appeared to utilize a different mechanism to protect D. radiodurans against DNA damage stresses that require direct protein–DNA binding. Many DNA-binding proteins locally protect DNA from reactive oxygen species in vitro, and this phenomenon
is indeed the basis for DNA footprinting studies. Protection may also be related to alterations in DNA conformation. These proteins, like histone-like proteins, may be preferentially oxidized over DNA and become sacrificial targets. DR0199 protects double-stranded DNA from digestion, which should help maintain the integrity of DNA fragments generated in response to DNA damage,
regardless of whether such fragments are a result of the direct action of the damaging agent or produced as a consequence of the repair processes. By limiting degradation,proteins that protect DNA could enhance DNA damage tolerance and cell survival. In other words, the DR0199 protein may play an important role in preserving genetic information and contribute to the DNA damage tolerance in this species.