1. Institute of Applied Synthetic Chemistry, OC-163, TU Wien, Getreidemarkt 9, 1060 Vienna, Austria
2. Institute of Biochemistry, Dept. of Biotechnology & Enzyme Catalysis, University of Greifswald, Felix-Hausdorff-Str. 4, 17489 Greifswald, Germany
3. Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford St, Cambridge, Massachusetts 02138, United States