1. Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada
2. Department of Chemistry, McGill University, Montreal, QC H3A 0B8, Canada
3. Institute for Organic Chemistry and Chemical Biology, Goethe University, Frankfurt am Main 60438, Germany
4. Center of Biomolecular Magnetic Resonance (BMRZ), Goethe University, Frankfurt am Main 60438, Germany