2015 Nobel Prize in Chemistry award for discovery of DNA repair

by Stephanie M. Halmo

Announced on Wednesday, October 7th, the 2015 Nobel Prize in Chemistry was awarded to Tomas Lindahl, Paul Modrich, and Aziz Sancar for their studies on DNA self-repair. These scientists each discovered a different mechanism by which DNA—usually thought of as a stable molecule—can be repaired.

These scientists each discovered a different way organisms repair their own DNA—mismatch repair, nucleotide excision repair, and  base excision repair. These repair mechanisms, combined with several other mechanisms of repair, fix thousands of spontaneous errors and instances of DNA damage in our cells every day.

DNA origami

Photo by Alex Bateman

In 1989, Modrich identified the molecular mechanism of mismatch repair, a natural process found in bacteria and humans. In mismatch repair, faulty base pairs are recognized and enzymes remove a portion of the incorrect DNA strand.

In 1983, Sancar began his discovery of nucleotide excision repair, the system used to correct DNA damage caused by UV radiation. In nucleotide excision repair, enzymes identify areas of UV damage in DNA and remove them by cutting out a small fragment.

In 1974, Lindahl uncovered the molecular mechanism of base excision repair in bacterial DNA. During base excision repair, enzymes recognize a defective base and remove it.

About the author

Stephanie HalmoStephanie Halmo is a former middle school science teacher turned graduate student, actively pursuing her Ph.D. in biochemistry from the University of Georgia. In her spare time she likes to dance, volunteer at local schools and tie-dye anything she can get her hands on. You can connect with Stephanie on Twitter and Instagram @shalmo or by email: shalmo27@uga.edu