1. Department of Biophysics and Biochemistry, Graduate School of Science, The University of Tokyo, Hongo, Bunkyo-Ku, Tokyo 113-0032, Japan, Department of Biochemistry, Institute for Developmental Research, Aichi Human Service Center, Kasugai, Aichi 480-0392, Japan, Department of Virology II, National Institute of Infectious Diseases, Tokyo 162-8640, Japan, International Institute for Advanced Research, Matsushita Electric Industrial Co., Ltd., Kyoto 619-0237, Japan, and Institute for Protein Research, Osaka...