1. School of Life Sciences, Centre for Protein Science and Crystallography, State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong, China
2. Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
3. Department of Biology, Faculty of Science, Niigata University, Ikarashi 2-8050, Nishi-ku, Niigata 950-2191, Japan