1. Laboratory for Nonnatural Amino Acid Technology RIKEN Center for Biosystems Dynamics Research 1-7-22 Suehiro-cho, Tsurumi-ku Yokohama 230-0045 Japan
2. Research Institute for Bioscience Products and Fine Chemicals Ajinomoto Co., Inc. 1-1 Suzuki-Cho, Kawasaki-Ku Kawasaki 210-8681 Japan
3. Laboratory for Translation Structural Biology RIKEN Center for Biosystems Dynamics Research 1-7-22 Suehiro-cho, Tsurumi-ku Yokohama 230-0045 Japan