1. RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo, Hyogo 679-5148, Japan
2. Department of Biology, Rensselaer Polytechnic Institute, 110 Eighth Street, Troy, New York 12180-3590, United States
3. Japan Synchrotron Radiation Research Institute, 1-1-1, Kouto, Sayo, Hyogo 679-5198 Japan