1
Nei-Li Chan is at the Institute of Biochemistry, College of Life Sciences, National Chung Hsing University, Taichung City, 40227, Taiwan
2
Christopher P. Hill is in the Department of Biochemistry, University of Utah School of Medicine, 50 N. Medical Drive, Salt Lake City, Utah 84132, USA.
Recent crystal structures suggest models for how an asymmetric E2/E2-like protein complex synthesizes a polyubiquitin chain that functions in DNA repair and NF-B activation pathways.