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Visualization of DNA‐induced conformational changes in the DNA repair kinase DNA‐PKcs
Author(s) -
Boskovic Jasminka,
RiveraCalzada Angel,
Maman Joseph D.,
Chacón Pablo,
Willison Keith R.,
Pearl Laurence H.,
Llorca Oscar
Publication year - 2003
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1093/emboj/cdg555
Subject(s) - biology , dna , dna pkcs , dna repair , microbiology and biotechnology , visualization , genetics , computational biology , biophysics , artificial intelligence , computer science
The catalytic subunit of the DNA‐dependent protein kinase (DNA‐PKcs) is essential for the repair of double‐stranded DNA breaks (DSBs) in non‐ homologous end joining (NHEJ) and during V(D)J recombination. DNA‐PKcs binds single‐ and double‐stranded DNA in vitro , and in vivo the Ku heterodimer probably helps recruit it to DSBs with high affinity. Once loaded onto DNA, DNA‐PKcs acts as a scaffold for other repair factors to generate a multiprotein complex that brings the two DNA ends together. Human DNA‐PKcs has been analysed by electron microscopy in the absence and presence of double‐stranded DNA, and the three‐dimensional reconstruction of DNA‐bound DNA‐PKcs displays large conformational changes when compared with the unbound protein. DNA‐PKcs seems to use a palm‐like domain to clip onto the DNA, and this new conformation correlates with the activation of the kinase. We suggest that the observed domain movements might help the binding and maintenance of DNA‐PKcs' interaction with DNA at the sites of damage, and that these conformational changes activate the kinase.