[1] Ecole Normale Super, Lab Regulat Express Genet, CNRS, UMR 8541, F-75230 Paris 05, France
[2] Ecole Super Phys & Chim Ind Ville Paris, CNRS, UMR 7637, F-75005 Paris, France
[3] Univ Naples Federico II, Dipartimento Genet Biol Gen & Mol, I-80134 Naples, Italy