The Three-dimensional Structure of the C-terminal DNA-binding Domain of Human Ku70

Ziming Zhang, Lingyang Zhu, Donghai Lin, Fanqing Chen, David J. Chen, Yuan Chen

Research output: Contribution to journalArticlepeer-review

57 Scopus citations


The proteins Ku70 (69.8 kDa) and Ku80 (82.7 kDa) form a heterodimeric complex that is an essential component of the nonhomologous end joining DNA double-strand break repair pathway in mammalian cells. Interaction of Ku with DNA is central for the functions of Ku. Ku70, which is mainly responsible for the DNA binding activity of the Ku heterodimer, contains two DNA-binding domains. We have solved the solution structure of the Ku80-independent DNA-binding domain of Ku70 encompassing residues 536-609 using nuclear magnetic resonance spectroscopy. Residues 536-560 are highly flexible and have a random structure but form specific interactions with DNA. Residues 561-609 of Ku70 form a well defined structure with 3 α-helices and also interact with DNA. The three-dimensional structure indicates that all conserved hydrophobic residues are in the hydrophobic core and therefore may be important for structural integrity. Most of the conserved positively charged residues are likely to be critical for DNA recognition. The C-terminal DNA-binding domain of Ku70 contains a helix-extended strand-helix motif, which occurs in other nucleic acid-binding proteins and may represent a common nucleic acid binding motif.

Original languageEnglish (US)
Pages (from-to)38231-38236
Number of pages6
JournalJournal of Biological Chemistry
Issue number41
StatePublished - Oct 12 2001

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology


Dive into the research topics of 'The Three-dimensional Structure of the C-terminal DNA-binding Domain of Human Ku70'. Together they form a unique fingerprint.

Cite this