1. Institut Pasteur, Université Paris Cité, Department of Structural Biology and Chemistry, Laboratory for Bioorganic Chemistry of Nucleic Acids, CNRS UMR3523, 28, rue du Docteur Roux, 75724 Paris Cedex 15, France
2. Learning Planet Institute, 8, rue Charles V, 75004 Paris, France
3. School of Chemistry, University of Birmingham, Birmingham, B15 2TT, UK