Advanced Light Source (ALS) Beamlines Shed New Light on DNA Damage Repair

Summary

Double-strand breaks in DNA are particularly serious because they can lead to damage ranging from cell death in yeasts to cancer in humans. How these breaks get repaired is thus of great significance for cell biology and its practical applications. New research using small-angle x-ray scattering (SAXS) and x-ray diffraction stations at the ALS has just been published that helps explain how a key repair protein, Nbs1, guides the cellular response to double strand breaks and helps regulate the highly complex repair mechanism. A research team led by DOE scientist John Tainer of the Lawrence Berkeley National Laboratory used diffraction experiments to obtain structures of variants of Nbs1. SAXS experiments then were carried out that identified the shapes of three-protein complexes involving Nbs1 that carry out many of the steps in identifying and repairing double-strand DNA breaks. The research is published in the October 2 issue of Cell, with a preview article explaining its significance.

References

R. Scott Williams, et al., “Nbs1 Flexibly Tethers Ctp1 and Mre11-Rad50 to Coordinate DNA Double-Strand Break Processing and Repair”, Cell, Volume 139, pages 87-99 (October 2, 2009).

Karl-Peter Hopfner, “Preview: DNA Double-Strand Breaks Come into Focus”, Cell, Volume 139, pages 25-27 (October 2, 2009).