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From Proteopedia
Crystal structure of a poly(ADP-ribose) glycohydrolase
Structural highlights
DiseaseADPRS_HUMAN The disease is caused by variants affecting the gene represented in this entry. FunctionADPRS_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).[1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] Publication Abstract from PubMedADP-ribosylation of proteins plays key roles in multiple biological processes, including DNA damage repair. Recent evidence suggests that serine is an important acceptor for ADP-ribosylation, and that serine ADP-ribosylation is hydrolyzed by ADP-ribosylhydrolase 3 (ARH3 or ADPRHL2). However, the structural details in ARH3-mediated hydrolysis remain elusive. Here, we determined the structure of ARH3 in a complex with ADP-ribose (ADPR). Our analyses revealed a group of acidic residues in ARH3 that keep two Mg2+ ions at the catalytic center for hydrolysis of Ser-linked ADP-ribosyl group. In particular, dynamic conformational changes involving Glu41 were observed in the catalytic center. Our observations suggest that Mg2+ ions together with Glu41 and water351 are likely to mediate the cleavage of the glycosidic bond in the serine-ADPR substrate. Moreover, we found that ADPR is buried in a groove and forms multiple hydrogen bonds with the main chain and side chains of ARH3 residues. On the basis of these structural findings, we used site -directed mutagenesis to examine the functional roles of key residues in the catalytic pocket of ARH3 in mediating the hydrolysis of ADP-ribosyl from serine and DNA damage repair. Moreover, we noted that ADPR recognition is essential for the recruitment of ARH3 to DNA lesions. Taken together, our study provides structural and functional insights into the molecular mechanism by which ARH3 hydrolyzes ADP-ribosyl group from serine and contributes to DNA damage repair. Structure-function analyses reveal the mechanism of the ARH3-dependent hydrolysis of ADP-ribosylation.,Wang M, Yuan Z, Xie R, Ma Y, Liu X, Yu X J Biol Chem. 2018 Jul 25. pii: RA118.004284. doi: 10.1074/jbc.RA118.004284. PMID:30045870[12] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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Categories: Homo sapiens | Large Structures | Liu X | Ma Y | Wang J | Wang M | Yuan Z
