Researchers of the University of Oulu, Finland, have for the first time uncovered the molecular structure of a key protein, PARP2, when bound to damaged DNA. PARP2 is one of the key enzymes protecting and maintaining our genomes that continuously get damaged by chemicals and radiation from our environment. The new study shows in detail the structure of an activated PARP2 enzyme in complex with oligonucleotides mimicking a damaged DNA.