1. Department of Molecular Biology and Genetics, Aarhus University, Aarhus C 8000, Denmark
2. Department of Molecular Biology and Genetics, Aarhus Institute of Advanced Studies, Aarhus University, Aarhus C 8000, Denmark
3. Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense M 5230, Denmark
4. Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY 10016