1. Contribution from the Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita 565-0871, Japan, Genome Sciences Center, RIKEN Yokohama Institute, 1-7-22 Suehirocho, Tsurumi-ku, Yokohama 230-0045, Japan, and Chemical Resources Laboratory, Tokyo Institute of Technology, Nagatsuta 4259, Yokohama 226-8503, Japan