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-Structure paper
Title | Cryo-EM structure of the DNA-PK holoenzyme. |
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Journal, issue, pages | Proc Natl Acad Sci U S A, Vol. 114, Issue 28, Page 7367-7372, Year 2017 |
Publish date | Jul 11, 2017 |
![]() | Humayun Sharif / Yang Li / Yuanchen Dong / Liyi Dong / Wei Li Wang / Youdong Mao / Hao Wu / ![]() ![]() |
PubMed Abstract | DNA-dependent protein kinase (DNA-PK) is a large protein complex central to the nonhomologous end joining (NHEJ) DNA-repair pathway. It comprises the DNA-PK catalytic subunit (DNA-PKcs) and the ...DNA-dependent protein kinase (DNA-PK) is a large protein complex central to the nonhomologous end joining (NHEJ) DNA-repair pathway. It comprises the DNA-PK catalytic subunit (DNA-PKcs) and the heterodimer of DNA-binding proteins Ku70 and Ku80. Here, we report the cryo-electron microscopy (cryo-EM) structures of human DNA-PKcs at 4.4-Å resolution and the DNA-PK holoenzyme at 5.8-Å resolution. The DNA-PKcs structure contains three distinct segments: the N-terminal region with an arm and a bridge, the circular cradle, and the head that includes the kinase domain. Two perpendicular apertures exist in the structure, which are sufficiently large for the passage of dsDNA. The DNA-PK holoenzyme cryo-EM map reveals density for the C-terminal globular domain of Ku80 that interacts with the arm of DNA-PKcs. The Ku80-binding site is adjacent to the previously identified density for the DNA-binding region of the Ku70/Ku80 complex, suggesting concerted DNA interaction by DNA-PKcs and the Ku complex. |
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Methods | EM (single particle) |
Resolution | 4.4 - 5.8 Å |
Structure data | ![]() EMDB-8752: |
Source |
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![]() | DNA BINDING PROTEIN / DNAP / PIKK / NHEJ / V(D)J recombination |