Affiliation at the time of the award: Howard Hughes Medical Institute, Durham, NC, USA, Duke University School of Medicine, Durham, NC, USA
Prize motivation: "for mechanistic studies of DNA repair"
Prize share: 1/3
Living cells have DNA molecules that carry an organism's genes. For the organism to live and develop, its DNA cannot change. DNA molecules are not completely stable, and they can be damaged. In 1989, through studies of bacterial viruses, Paul Modrich showed how methyl groups attached to the DNA molecule act as signals for repairing incorrect replications of DNA. These discoveries have increased our understanding of how the living cell works, the causes of cancer and about aging processes.