1. EMBL Heidelberg Meyerhofstrasse 1 Heidelberg 69117 Germany
2. Novo Nordisk Foundation Center for Protein Research, Faculty of Health Sciences Blegdamsvej 3b Copenhagen N 2200 Denmark
3. Max‐Delbrueck‐Center for Molecular Medicine, Berlin‐Buch Robert‐Rossle‐Strasse 10 Berlin 13092 Germany