- PMID:
21936820
- Authors:
- Wu Q, Ochi T, Matak-Vinkovic D, Robinson CV, Chirgadze DY, Blundell TL
- Title:
- Non-homologous end-joining partners in a helical dance: structural studies of XLF-XRCC4 interactions.
- Journal:
- Biochem Soc Trans. 2011 Oct;39(5):1387-92, suppl 2 p following 1392.
- Abstract:
- XRCC4 (X-ray cross-complementation group 4) and XLF (XRCC4-like factor) are two essential interacting proteins in the human NHEJ (non-homologous end-joining) pathway that repairs DNA DSBs (double-strand breaks). The individual crystal structures show that the dimeric proteins are homologues with protomers containing head domains and helical coiled-coil tails related by approximate two-fold symmetry. Biochemical, mutagenesis, biophysical and structural studies have identified the regions of interaction between the two proteins and suggested models for the XLF-XRCC4 complex. An 8.5 A (1 A = 0.1 nm) resolution crystal structure of XLF-XRCC4 solved by molecular replacement, together with gel filtration and nano-ESI (nano-electrospray ionization)-MS results, demonstrates that XLF and XRCC4 dimers interact through their head domains and form an alternating left-handed helical structure with polypeptide coiled coils and pseudo-dyads of individual XLF and XRCC4 dimers at right angles to the helical axis.