The reference Wu et al., 2003, was incorrectly included in the paper. The correct reference (Wu-Baer et al., 2003) appears below.
Wu-Baer, F., K. Lagrazon, W. Yuan, and R. Baer.
2003. The BRCA1/BARD1 heterodimer assembles polyubiquitin chains through an unconventional linkage involving lysine residue K6 of ubiquitin.
J. Biol. Chem. 278:
The Rockefeller University Press