International Journal of Molecular Sciences Review PARP Power: A Structural Perspective on PARP1, PARP2, and PARP3 in DNA Damage Repair and Nucleosome Remodelling Lotte van Beek 1,† , Éilís McClay 2,†, Saleha Patel 3, Marianne Schimpl 1 , Laura Spagnolo 2,* and Taiana Maia de Oliveira 1,* 1 Structure and Biophysics, Discovery Sciences, R&D, AstraZeneca, Cambridge CB4 0WG, UK;
[email protected] (L.v.B.);
[email protected] (M.S.) 2 Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, Garscube Campus, University of Glasgow, Glasgow G61 1QQ, UK;
[email protected] 3 Discovery Biology, Discovery Sciences, R&D, AstraZeneca, Cambridge CB4 0WG, UK;
[email protected] * Correspondence:
[email protected] (L.S.);
[email protected] (T.M.d.O.) † These authors contributed equally to this work. Abstract: Poly (ADP-ribose) polymerases (PARP) 1-3 are well-known multi-domain enzymes, catalysing the covalent modification of proteins, DNA, and themselves. They attach mono- or poly-ADP-ribose to targets using NAD+ as a substrate. Poly-ADP-ribosylation (PARylation) is cen- tral to the important functions of PARP enzymes in the DNA damage response and nucleosome remodelling. Activation of PARP happens through DNA binding via zinc fingers and/or the WGR domain. Modulation of their activity using PARP inhibitors occupying the NAD+ binding site has proven successful in cancer therapies. For decades, studies set out to elucidate their full-length molecular structure and activation mechanism. In the last five years, significant advances have Citation: van Beek, L.; McClay, É.; progressed the structural and functional understanding of PARP1-3, such as understanding allosteric Patel, S.; Schimpl, M.; Spagnolo, L.; activation via inter-domain contacts, how PARP senses damaged DNA in the crowded nucleus, and Maia de Oliveira, T.