This article refers to:
Volume 28, no. 14, p. 4620-4628, 2008. Page 4627: The Acknowledgment section was inadvertently omitted and should appear as shown below.
ACKNOWLEDGMENTS
F.C.-L. is a recipient of an EMBO long-term fellowship (ALTF956-2006). K.W.C. is funded by the MRC (G0400959 and G0600776), BBSRC (BB/C516595/1), and the European Community (integrated project DNA Repair LSHG-CT-2005-512113).