Molecular mechanisms of assembly and TRIP13-mediated remodeling of the human Shieldin complex Journal Article


Authors: Xie, W.; Wang, S.; Wang, J.; de la Cruz, M. J.; Xu, G.; Scaltriti, M.; Patel, D. J.
Article Title: Molecular mechanisms of assembly and TRIP13-mediated remodeling of the human Shieldin complex
Abstract: The Shieldin complex, composed of REV7, SHLD1, SHLD2, and SHLD3, protects DNA double-strand breaks (DSBs) to promote nonhomologous end joining. The AAA+ ATPase TRIP13 remodels Shieldin to regulate DNA repair pathway choice. Here we report crystal structures of human SHLD3–REV7 binary and fused SHLD2–SHLD3–REV7 ternary complexes, revealing that assembly of Shieldin requires fused SHLD2–SHLD3 induced conformational heterodimerization of open (O-REV7) and closed (C-REV7) forms of REV7. We also report the cryogenic electron microscopy (cryo-EM) structures of the ATPγS-bound fused SHLD2–SHLD3–REV7–TRIP13 complexes, uncovering the principles underlying the TRIP13-mediated disassembly mechanism of the Shieldin complex. We demonstrate that the N terminus of REV7 inserts into the central channel of TRIP13, setting the stage for pulling the unfolded N-terminal peptide of C-REV7 through the central TRIP13 hexameric channel. The primary interface involves contacts between the safety-belt segment of C-REV7 and a conserved and negatively charged loop of TRIP13. This process is mediated by ATP hydrolysis-triggered rotatory motions of the TRIP13 ATPase, thereby resulting in the disassembly of the Shieldin complex. © 2021 National Academy of Sciences. All rights reserved.
Keywords: shieldin assembly; shld2–shld3–rev7 complex; shld2–shld3–rev7–trip13 complex; shld3–rev7 complex; trip13-mediated disassembly of shieldin
Journal Title: Proceedings of the National Academy of Sciences of the United States of America
Volume: 118
Issue: 8
ISSN: 0027-8424
Publisher: National Academy of Sciences  
Date Published: 2021-02-23
Start Page: e2024512118
Language: English
DOI: 10.1073/pnas.2024512118
PUBMED: 33597306
PROVIDER: scopus
PMCID: PMC7923543
DOI/URL:
Notes: Article -- Export Date: 1 April 2021 -- Source: Scopus
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  1. Dinshaw J Patel
    477 Patel
  2. Maurizio Scaltriti
    169 Scaltriti
  3. Wei Xie
    19 Xie
  4. Guotai Xu
    14 Xu
  5. Juncheng Wang
    12 Wang
  6. Shengliu Wang
    3 Wang