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-Structure paper
Title | Structure of an activated DNA-PK and its implications for NHEJ. |
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Journal, issue, pages | Mol Cell, Vol. 81, Issue 4, Page 801-810.e3, Year 2021 |
Publish date | Feb 18, 2021 |
Authors | Xuemin Chen / Xiang Xu / Yun Chen / Joyce C Cheung / Huaibin Wang / Jiansen Jiang / Natalia de Val / Tara Fox / Martin Gellert / Wei Yang / |
PubMed Abstract | DNA-dependent protein kinase (DNA-PK), like all phosphatidylinositol 3-kinase-related kinases (PIKKs), is composed of conserved FAT and kinase domains (FATKINs) along with solenoid structures made of ...DNA-dependent protein kinase (DNA-PK), like all phosphatidylinositol 3-kinase-related kinases (PIKKs), is composed of conserved FAT and kinase domains (FATKINs) along with solenoid structures made of HEAT repeats. These kinases are activated in response to cellular stress signals, but the mechanisms governing activation and regulation remain unresolved. For DNA-PK, all existing structures represent inactive states with resolution limited to 4.3 Å at best. Here, we report the cryoelectron microscopy (cryo-EM) structures of DNA-PKcs (DNA-PK catalytic subunit) bound to a DNA end or complexed with Ku70/80 and DNA in both inactive and activated forms at resolutions of 3.7 Å overall and 3.2 Å for FATKINs. These structures reveal the sequential transition of DNA-PK from inactive to activated forms. Most notably, activation of the kinase involves previously unknown stretching and twisting within individual solenoid segments and loosens DNA-end binding. This unprecedented structural plasticity of helical repeats may be a general regulatory mechanism of HEAT-repeat proteins. |
External links | Mol Cell / PubMed:33385326 / PubMed Central |
Methods | EM (single particle) / X-ray diffraction |
Resolution | 3.21 - 4.3 Å |
Structure data | EMDB-22618, PDB-7k0y: EMDB-22619, PDB-7k10: EMDB-22620, PDB-7k11: EMDB-22622, PDB-7k19: EMDB-22623, PDB-7k1b: EMDB-22624, PDB-7k1j: EMDB-22625, PDB-7k1k: EMDB-22626, PDB-7k1n: PDB-7k17: |
Source |
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Keywords | DNA BINDING PROTEIN/DNA / DNA-dependent Protein Kinase / DNA repair / NHEJ / V(D)J recombination / DNA BINDING PROTEIN / DNA BINDING PROTEIN-DNA complex / PIKK kinase |