PARIS, Sept. 28 (UPI) -- French scientists say they might have determined how an extremophile bacterium is able to reassemble its genome after being shattered by radiation.
The scientists, led by Miroslav Radman at the University of Paris, say the bacterium Deinococcus radiodurans is one of the few organisms that can withstand extreme bouts of desiccation and ionizing radiation.
In a study appearing online this week at the journal Nature's Web site, Radman and colleagues describe a novel two-stage DNA repair process that enables the bacterium to rebuild its genome.
First, the randomly broken fragments have one strand at each end chewed away to leave a single-strand tail. Those tails can find a complementary sequence, and an enzyme -- called DNA polymerase -- extends them to form long single-stranded DNA tails.
Second, the complementary long tails pair together, forming long double-stranded DNA molecules that are processed into the original circular genome.
The researchers say the process is efficient and accurate and other desiccation-resistant organisms, such as rotifers, might have evolved a similar repair system.
The study is to appear in the printed edition of Nature at a later date.
