1. Institute of Microbiology, ETH Zurich, Zürich 8093, Switzerland
2. Department of Chemistry and Biochemistry Program, Bethel University, Saint Paul, Minnesota, USA 55112
3. Department of Biology and Biochemistry Program, Hamline University, Saint Paul, Minnesota, USA 55104
4. Department of Biochemistry, Molecular Biology and Biophysics and Biotechnology Institute, University of Minnesota, Saint Paul, Minnesota, USA 55108