1. Yoshida Biological Laboratory Takehanasotoda‐cho, Yamashina‐ku Kyoto 607‐8081 Japan
2. CREST, Japan Science and Technology Kawaguchi Saitama 332‐0012 Japan
3. RIKEN SPring‐8 Center 1‐1‐1 Kouto Sayo Hyogo 679‐5148 Japan
4. Academia Sinica Institute of Biological Chemistry 128 Academia Road Sec. 2 Nankang Taipei 115 Taiwan