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6m3i
From Proteopedia
Crystal structure of HPF1/PARP1 complex
Structural highlights
FunctionHPF1_HUMAN Acts as a cofactor for serine ADP-ribosylation by conferring serine specificity on PARP1 and PARP2: interacts with PARP1 and PARP2 and is able to change amino acid specificity toward serine (PubMed:28190768, PubMed:29480802). Promotes histone serine ADP-ribosylation in response to DNA damage, limiting DNA damage-induced PARP1 hyper-automodification, and ensuring genome stability (PubMed:27067600, PubMed:28190768). Serine ADP-ribosylation of proteins constitutes the primary form of ADP-ribosylation of proteins in response to DNA damage (PubMed:29480802). HPF1 also promotes tyrosine ADP-ribosylation, probably by conferring tyrosine specificity on PARP1 (PubMed:30257210).[1] [2] [3] [4] Publication Abstract from PubMedUpon binding to DNA breaks, poly(ADP-ribose) polymerase 1 (PARP1) ADP-ribosylates itself and other factors to initiate DNA repair. Serine is the major residue for ADP-ribosylation upon DNA damage, which strictly depends on HPF1. Here, we report the crystal structures of human HPF1/PARP1-CAT DeltaHD complex at 1.98 A resolution, and mouse and human HPF1 at 1.71 A and 1.57 A resolution, respectively. Our structures and mutagenesis data confirm that the structural insights obtained in a recent HPF1/PARP2 study by Suskiewicz et al. apply to PARP1. Moreover, we quantitatively characterize the key residues necessary for HPF1/PARP1 binding. Our data show that through salt-bridging to Glu284/Asp286, Arg239 positions Glu284 to catalyze serine ADP-ribosylation, maintains the local conformation of HPF1 to limit PARP1 automodification, and facilitates HPF1/PARP1 binding by neutralizing the negative charge of Glu284. These findings, along with the high-resolution structural data, may facilitate drug discovery targeting PARP1. HPF1 remodels the active site of PARP1 to enable the serine ADP-ribosylation of histones.,Sun FH, Zhao P, Zhang N, Kong LL, Wong CCL, Yun CH Nat Commun. 2021 Feb 15;12(1):1028. doi: 10.1038/s41467-021-21302-4. PMID:33589610[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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