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-Structure paper
Title | Cryo-EM visualization of DNA-PKcs structural intermediates in NHEJ. |
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Journal, issue, pages | Sci Adv, Vol. 9, Issue 22, Page eadg2838, Year 2023 |
Publish date | Jun 2, 2023 |
Authors | Siyu Chen / Alex Vogt / Linda Lee / Tasmin Naila / Ryan McKeown / Alan E Tomkinson / Susan P Lees-Miller / Yuan He / |
PubMed Abstract | DNA double-strand breaks (DSBs), one of the most cytotoxic forms of DNA damage, can be repaired by the tightly regulated nonhomologous end joining (NHEJ) machinery (Stinson and Loparo and Zhao ). ...DNA double-strand breaks (DSBs), one of the most cytotoxic forms of DNA damage, can be repaired by the tightly regulated nonhomologous end joining (NHEJ) machinery (Stinson and Loparo and Zhao ). Core NHEJ factors form an initial long-range (LR) synaptic complex that transitions into a DNA-PKcs (DNA-dependent protein kinase, catalytic subunit)-free, short-range state to align the DSB ends (Chen ). Using single-particle cryo-electron microscopy, we have visualized three additional key NHEJ complexes representing different transition states, with DNA-PKcs adopting distinct dimeric conformations within each of them. Upon DNA-PKcs autophosphorylation, the LR complex undergoes a substantial conformational change, with both Ku and DNA-PKcs rotating outward to promote DNA break exposure and DNA-PKcs dissociation. We also captured a dimeric state of catalytically inactive DNA-PKcs, which resembles structures of other PIKK (Phosphatidylinositol 3-kinase-related kinase) family kinases, revealing a model of the full regulatory cycle of DNA-PKcs during NHEJ. |
External links | Sci Adv / PubMed:37256947 / PubMed Central |
Methods | EM (single particle) |
Resolution | 3.6 - 14.0 Å |
Structure data | EMDB-28731, PDB-8ez9: EMDB-28732, PDB-8eza: EMDB-28733, PDB-8ezb: EMDB-28734: DNA-PKcs monomer in dimer DNA-PKcs complex EMDB-28735: DNAPKcs-Ku-LigIV(BRCT)-PAXX-DNA subcomplex in PAXX-LR complex EMDB-28736: XRCC4-XLF-XRCC4 subcomplex of PAXX-LR complex EMDB-28737: DNA-PKcs without N-terminus in PAXX-LR-ATP complex EMDB-28738: DNAPKcs-Ku-DNA subcomplex in PAXX-LR-ATP complex EMDB-28739: XRCC4-XLF-XRCC4 subcomplex in LR-ATP complex |
Chemicals | ChemComp-ATP: ChemComp-MG: |
Source |
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Keywords | DNA BINDING PROTEIN / Dimer / Kinase / Complex / NHEJ / DNA BINDING PROTEIN/DNA / DNA BINDING PROTEIN-DNA complex |