2015 Nobel Prize in Chemistry was awarded to Tomas Lindahl, Paul Modrich, and Aziz Sancar for their studies of DNA repair. This was a huge surprise to me. There is no question that DNA repair is important. But it wasn't clear to me who should win the Nobel Prize for DNA repair. This year's Lasker Award also recognized works on DNA repair, but it went instead for Stephen Elledge and Evelyn Witkin. That selection was not obvious to me, either, although I knew that Stephen Elledge had done impressive works and had also received Gairdner Award, Rosenstiel Award, and Dickson Prize. It seemed to me that there are so many aspects to DNA repair pathways and there are many other people who have also contributed to this field. Larry Moran mentions Philip Hanawalt as someone who may have been overlooked. A commentator in In The Pipeline blog mentions Richard Kolodner and Thomas Kunkel as some other important contributors in the field while noting that Paul Modrich often beat Richard Kolodner in tight races.
This is probably a case where there is no perfect answer, but at least there seems to be a logic to the decision by the Nobel committee. The works of these three elucidated details of three DNA repair mechanisms, namely base excision repair, nucleotide excision repair, and mismatch repair. They did this by establishing the enzymatic reactions in the test tubes. So, the nature of their studies fits with the Chemistry Prize. All of these mechanisms deal with DNA damages that occur on one strand of DNA. In comparison, my impression is that someone like Stephen Elledge has worked on cellular responses when the DNA is damaged and the nature of the damages include cuts on two strands of DNA. He has mainly used genetic approaches to understand the signaling cascades and the systematic responses rather than the detailed biochemistry of the repair processes. So, what Elledge did can be considered more genetic and biological and less chemical. And of course by focusing on base excision repair, nucleotide excision repair, and mismatch repair, the Nobel committee was able to keep the number of recipients to three.
Ultimately, the Nobel committee has the right to choose the recipients that they like. We tend to scrutinize the Nobel Prize much more than we do other prizes, but the Nobel Prize is not fundamentally different from other prizes. In the past, the Nobel Prize often went to people who had already been recognized by other major prizes, but it is interesting that they made a little surprising choice this year. And considering the importance of DNA repair, they didn't make a bad choice.