4A0D

Structure of unliganded human PARG catalytic domain

Summary for 4A0D

• Entry DOI: 10.2210/pdb4a0d/pdb
• Descriptor: POLY(ADP-RIBOSE) GLYCOHYDROLASE, (2S,3S)-1,4-DIMERCAPTOBUTANE-2,3-DIOL, GLYCEROL, ... (5 entities in total)
• Functional Keywords: hydrolase
• Biological source: HOMO SAPIENS (HUMAN)
• Cellular location: Isoform 1: Nucleus. Isoform 2: Cytoplasm. Isoform 3: Cytoplasm. Isoform 4: Cytoplasm. Isoform 5: Mitochondrion matrix: Q86W56
• Total number of polymer chains: 1
• Total formula weight: 61729.11

Authors

Brassington, C.,Ellston, J.,Hassall, G.,Holdgate, G.,McAlister, M.,Overman, R.,Smith, G.,Tucker, J.A.,Watson, M. (deposition date: 2011-09-08, release date: 2012-10-17, Last modification date: 2013-01-16)

Primary citation

Tucker, J.A.,Bennett, N.,Brassington, C.,Durant, S.T.,Hassall, G.,Holdgate, G.,Mcalister, M.,Nissink, J.W.M.,Truman, C.,Watson, M.
Structures of the Human Poly (Adp-Ribose) Glycohydrolase Catalytic Domain Confirm Catalytic Mechanism and Explain Inhibition by Adp-Hpd Derivatives.
Plos One, 7:50889-, 2012

PubMed Abstract: Poly(ADP-ribose) glycohydrolase (PARG) is the only enzyme known to catalyse hydrolysis of the O-glycosidic linkages of ADP-ribose polymers, thereby reversing the effects of poly(ADP-ribose) polymerases. PARG deficiency leads to cell death whilst PARG depletion causes sensitisation to certain DNA damaging agents, implicating PARG as a potential therapeutic target in several disease areas. Efforts to develop small molecule inhibitors of PARG activity have until recently been hampered by a lack of structural information on PARG. We have used a combination of bio-informatic and experimental approaches to engineer a crystallisable, catalytically active fragment of human PARG (hPARG). Here, we present high-resolution structures of the catalytic domain of hPARG in unliganded form and in complex with three inhibitors: ADP-ribose (ADPR), adenosine 5'-diphosphate (hydroxymethyl)pyrrolidinediol (ADP-HPD) and 8-n-octyl-amino-ADP-HPD. Our structures confirm conservation of overall fold amongst mammalian PARG glycohydrolase domains, whilst revealing additional flexible regions in the catalytic site. These new structures rationalise a body of published mutational data and the reported structure-activity relationship for ADP-HPD based PARG inhibitors. In addition, we have developed and used biochemical, isothermal titration calorimetry and surface plasmon resonance assays to characterise the binding of inhibitors to our PARG protein, thus providing a starting point for the design of new inhibitors.

PubMed: 23251397
DOI: 10.1371/JOURNAL.PONE.0050889

Experimental method

X-RAY DIFFRACTION (1.75 Å)