6wwa
Crystal structure of human SHLD2-SHLD3-REV7 complex
Structural highlights
FunctionMD2L2_HUMAN Adapter protein able to interact with different proteins and involved in different biological processes. Mediates the interaction between the error-prone DNA polymerase zeta catalytic subunit REV3L and the inserter polymerase REV1, thereby mediating the second polymerase switching in translesion DNA synthesis. Translesion DNA synthesis releases the replication blockade of replicative polymerases, stalled in presence of DNA lesions. May also regulate another aspect of cellular response to DNA damage through regulation of the JNK-mediated phosphorylation and activation of the transcriptional activator ELK1. Inhibits the FZR1- and probably CDC20-mediated activation of the anaphase promoting complex APC thereby regulating progression through the cell cycle. Regulates TCF7L2-mediated gene transcription and may play a role in epithelial-mesenchymal transdifferentiation.[1] [2] [3] [4] [5] Publication Abstract from PubMedThe 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 ATPgammaS-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. Molecular mechanisms of assembly and TRIP13-mediated remodeling of the human Shieldin complex.,Xie W, Wang S, Wang J, de la Cruz MJ, Xu G, Scaltriti M, Patel DJ Proc Natl Acad Sci U S A. 2021 Feb 23;118(8):e2024512118. doi: , 10.1073/pnas.2024512118. PMID:33597306[6] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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