1. LIMES Chemical Biology UnitUniversität Bonn Gerhard-Domagk-Straße 1 53121 Bonn Germany
2. Max-Planck-Fellow Chemische BiologieCenter of Advanced European Studies and Research (caesar) Ludwig-Erhard-Allee 2 53175 Bonn Germany
3. Department of Biomolecular EngineeringGraduate School of EngineeringNagoya University Furo-cho, Chikusa-ku Nagoya 464-8603 Japan