5dsy
Crystal structure of constitutively active PARP-2
Structural highlights
FunctionPARP2_HUMAN Involved in the base excision repair (BER) pathway, by catalyzing the poly(ADP-ribosyl)ation of a limited number of acceptor proteins involved in chromatin architecture and in DNA metabolism. This modification follows DNA damages and appears as an obligatory step in a detection/signaling pathway leading to the reparation of DNA strand breaks. Publication Abstract from PubMedPoly(ADP-ribose) polymerase-1 (PARP-1) creates the posttranslational modification PAR from substrate NAD(+) to regulate multiple cellular processes. DNA breaks sharply elevate PARP-1 catalytic activity to mount a cell survival repair response, whereas persistent PARP-1 hyperactivation during severe genotoxic stress is associated with cell death. The mechanism for tight control of the robust catalytic potential of PARP-1 remains unclear. By monitoring PARP-1 dynamics using hydrogen/deuterium exchange-mass spectrometry (HXMS), we unexpectedly find that a specific portion of the helical subdomain (HD) of the catalytic domain rapidly unfolds when PARP-1 encounters a DNA break. Together with biochemical and crystallographic analysis of HD deletion mutants, we show that the HD is an autoinhibitory domain that blocks productive NAD(+) binding. Our molecular model explains how PARP-1 DNA damage detection leads to local unfolding of the HD that relieves autoinhibition, and has important implications for the design of PARP inhibitors. PARP-1 Activation Requires Local Unfolding of an Autoinhibitory Domain.,Dawicki-McKenna JM, Langelier MF, DeNizio JE, Riccio AA, Cao CD, Karch KR, McCauley M, Steffen JD, Black BE, Pascal JM Mol Cell. 2015 Dec 3;60(5):755-68. doi: 10.1016/j.molcel.2015.10.013. Epub 2015, Nov 25. PMID:26626480[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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