1. Computational Bioinformatics Laboratory, Department of Computing, Imperial College London, 180 Queen’s Gate, London SW7 2AZ, United Kingdom, Molecular Medicine Research Laboratories, Drug Discovery Research, Astellas Pharma Inc., 21 Miyukigaoka, Tsukuba, Ibaraki 305-8585, Japan, and Structural Bioinformatics Group, Center for Bioinformatics, Division of Molecular Biosciences, Imperial College London, London SW7 2AZ, United Kingdom