"It has been assumed in the past that double strand breaks are the most difficult class of DNA damage to repair and it is often presumed that they simply can not be repaired accurately," says Ramsden.

The team found that the protein Ku, which has long been appreciated for its ability to find chromosome breaks along a strand of DNA, actually removes the "dirt" at broken chromosome ends, allowing for much more accurate repair than believed possible.

"This protein actually heals at the nucleotide level as well as the level of the chromosome," says Ramsden, comparing its action to washing and disinfecting a cut before trying to sew it up to promote healing.

The team is hopeful that the discovery of this mechanism for DNA repair may lead to a target for treatment of age-related diseases caused by chromosome damage in the future.

Source: University of North Carolina School of Medicine