View source for 9rfd


==Human ADP-ribosylhydrolase 3 (ARH3) in complex with ADP==
<StructureSection load='9rfd' size='340' side='right'caption='[[9rfd]], [[Resolution|resolution]] 1.85&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[9rfd]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=9RFD OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=9RFD FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.85&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ACY:ACETIC+ACID'>ACY</scene>, <scene name='pdbligand=ADP:ADENOSINE-5-DIPHOSPHATE'>ADP</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=9rfd FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=9rfd OCA], [https://pdbe.org/9rfd PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=9rfd RCSB], [https://www.ebi.ac.uk/pdbsum/9rfd PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=9rfd ProSAT]</span></td></tr>
</table>
== Disease ==
[https://www.uniprot.org/uniprot/ADPRS_HUMAN ADPRS_HUMAN] The disease is caused by variants affecting the gene represented in this entry.
== Function ==
[https://www.uniprot.org/uniprot/ADPRS_HUMAN ADPRS_HUMAN] ADP-ribose glycohydrolase that preferentially hydrolyzes the scissile alpha-O-linkage attached to the anomeric C1'' position of ADP-ribose and acts on different substrates, such as proteins ADP-ribosylated on serine, free poly(ADP-ribose) and O-acetyl-ADP-D-ribose (PubMed:21498885, PubMed:30045870, PubMed:29907568, PubMed:30401461, PubMed:33186521). Specifically acts as a serine mono-ADP-ribosylhydrolase by mediating the removal of mono-ADP-ribose attached to serine residues on proteins, thereby playing a key role in DNA damage response (PubMed:28650317, PubMed:29234005, PubMed:30045870, PubMed:33186521). Serine ADP-ribosylation of proteins constitutes the primary form of ADP-ribosylation of proteins in response to DNA damage (PubMed:29480802, PubMed:33186521). Does not hydrolyze ADP-ribosyl-arginine, -cysteine, -diphthamide, or -asparagine bonds (PubMed:16278211). Also able to degrade protein free poly(ADP-ribose), which is synthesized in response to DNA damage: free poly(ADP-ribose) acts as a potent cell death signal and its degradation by ADPRHL2 protects cells from poly(ADP-ribose)-dependent cell death, a process named parthanatos (PubMed:16278211). Also hydrolyzes free poly(ADP-ribose) in mitochondria (PubMed:22433848). Specifically digests O-acetyl-ADP-D-ribose, a product of deacetylation reactions catalyzed by sirtuins (PubMed:17075046, PubMed:21498885). Specifically degrades 1''-O-acetyl-ADP-D-ribose isomer, rather than 2''-O-acetyl-ADP-D-ribose or 3''-O-acetyl-ADP-D-ribose isomers (PubMed:21498885).<ref>PMID:16278211</ref> <ref>PMID:17075046</ref> <ref>PMID:21498885</ref> <ref>PMID:22433848</ref> <ref>PMID:28650317</ref> <ref>PMID:29234005</ref> <ref>PMID:29480802</ref> <ref>PMID:29907568</ref> <ref>PMID:30045870</ref> <ref>PMID:30401461</ref> <ref>PMID:33186521</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Poly-ADP-ribosylation at sites of DNA damage, catalyzed by PARP enzymes, activates the DNA damage response, chromatin remodeling, and DNA repair. The modification is reversed by two enzymes in humans: PARG, which efficiently hydrolyzes the poly-ADP-ribose chains, and ARH3, which is the key enzyme for removing the last proximal mono-ADP-ribose from serine residues. While inhibitor development has largely focused on PARPs and PARG, no potent and selective inhibitors for ARH3 are currently available. We optimized a FRET-based competition assay for ARH3 and carried out high-throughput screening of small-molecule inhibitors. One hit compound, 1, with a potency of 22 muM was discovered, and through structure-activity relationship studies and synthesis, we improved its potency 10-fold to 2 muM (compound 27, MDOLL-0286). We demonstrate that the compound inhibits ARH3's poly-ADP-ribose hydrolytic activity on cellular substrates. Intriguingly, it does not effectively inhibit the hydrolysis of mono-ADP-ribosylation from natural protein substrates. This is despite the fact that the cocrystal structure of compound 1 bound to ARH3 reveals its overlap with the enzyme's ADP-ribose binding site, agreeing with the competition in the FRET assay. The first experimental ARH3 inhibitor complex provides a valuable starting point for developing more potent chemical probes to study DNA damage response mechanisms in the future.

Discovery and Structural Optimization of 2-Hydrazinopyrimidin-4-one Analogs Inhibiting Human ADP-Ribosylhydrolase ARH3.,Parviainen TAO, Duong MTH, Paakkonen J, Burdova K, Kuttichova B, Hanzlikova H, Lehtio L, Heiskanen JP ACS Chem Biol. 2025 Sep 15. doi: 10.1021/acschembio.5c00461. PMID:40952342<ref>PMID:40952342</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 9rfd" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Lehtio L]]
[[Category: Paakkonen J]]