Structural basis for allosteric PARP-1 retention on DNA breaks

DNA death grip Poly(ADP-ribose) polymerase–1 (PARP-1) binds to DNA breaks and recruits DNA repair components. Cancer-killing PARP-1 inhibitor (PARPi) compounds all block the same catalytic site but exhibit vastly different efficacy. Zandarashvili et al. investigated the molecular impact of PARPi binding to PARP-1 (see the Perspective by Slade and Eustermann). Different PARPi molecules perturb PARP-1 allostery in diverse manners: Some drive allostery to promote release of PARP-1 from DNA, and others drive allostery to promote retention. These insights help explain the different efficacies in the clinic and enable conversion of a pro-release, ineffective cancer-killing compound to a pro-retention, more effective PARPi. Science , this issue p. eaax6367 ; see also p. 30