1. Institut des Biomolécules Max Mousseron UMR5247, CNRS–Universités Montpellier 1 and Montpellier 2, CC17006, Place E. Bataillon, 34095 Montpellier, France
2. Department of Chemistry, Ben-Gurion University of the Negev, Be'er Sheva 84105, Israel
3. Laboratory of Molecular Biology, MRC, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH, UK