1. Division of Molecular and Life Sciences, Pohang University of Science and Technology, Pohang 790-783, Kyungbuk, South Korea
2. Department of Biochemistry, Fukui Medical University, Matsuoka 910-1193, Fukui, Japan
3. IMBA, Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Dr. Bohrgasse 3-5, A-1030 Vienna, Austria