1. Roche Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., Grenzacherstrasse 124, 4070 Basel, Switzerland
2. Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ, U.K.
3. Structural Biology, Genentech, Inc., 1 DNA Way, South San Francisco, California 94080, United States