When you stay out on the beach too long, high-energy ultraviolet light can cause adjacent bases in the DNA (thymine, the T in the genetic code) to link together. This forms a structure known as a (6-4) lesion. When that lesion is exposed to even more UV light, it twists into an even stranger shape called a “Dewar” isomer. In biology, this is rather bad news, as Dewar isomers cause kinks in the DNA’s double-helix spiral that disrupt copying the DNA and can lead to mutations or cancer.

To counter this effect, evolution shaped a specific enzyme called photolyase to hunt (6-4) lesions down and snap them back into their safe, stable forms.

The researchers realized that the Dewar isomer is essentially a molecular battery. This snap-back effect was exactly what Nguyen’s team was looking for, since it releases a lot of heat.