1. Department of Biochemistry and Molecular Biology, Faculty of Science, Saitama University, Saitama-shi, Saitama 338-8570
2. Department of Integrated Biosciences, Graduate School of Frontier Sciences, University of Tokyo, Kashiwanoha 5-1-5, Kashiwa, Chiba 277-8562
3. Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011
4. Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Tokyo 153-8902, Japan