1. Laboratory of Drug Metabolism and Pharmacokinetics; Showa Pharmaceutical University; Machida Tokyo 194-8543 Japan
2. Oxford University, Structural Genomics Consortium; Oxford OX3 7DQ
3. Institute of Structural and Molecular Biology; University College London; London WC1E 6BT
4. School of Biological and Chemical Sciences; Queen Mary University of London; London E1 4NS United Kingdom