This is possible thanks to an enzyme called DNA photolyase, which is so specialised that cryptochrome, a structurally similar molecule, is unable to do the same job. (sciencedaily.com)
Blaustein and Hays already knew that UV radiation damages DNA, and that an enzyme called photolyase can repair this damage. (newscientist.com)
This is due to electrostatic interactions between the positive charges on the protein surface of photolyase and the negatively charged backbone of the DNA. (sciencedaily.com)