Laboratory of Biomolecular Research, Paul Scherrer Institute, Villigen, Switzerland.|Laboratory of Biomolecular Research, Paul Scherrer Institute, Villigen, Switzerland.|RCSB Protein Data Bank, San Diego Supercomputing Center, University of California San Diego, La Jolla, California, United States of America.|Laboratory of Biomolecular Research, Paul Scherrer Institute, Villigen, Switzerland.|RCSB Protein Data Bank, San Diego Supercomputing Center, University of California San Diego, La Jolla, California, United States of America.|National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland, United States of America.