1. Laboratory of Molecular Biophysics and Department of Biochemistry, The Rex Richards Building, University of Oxford, South Parks Road, Oxford, OX1 3QU, U.K., C.N.R.S., Cell Cycle Group & UPS2682, Station Biologique, B.P. 74, 29682 Roscoff Cedex, Bretagne, France, Département de Recherches en Cancérologie, Université de Nantes, Inserm U692, 9 Quai Moncousu, 44093 Nantes Cedex 01, France, LBCMCP, UMR-CNRS 5088, IFR 109, Université Paul Sabatier Bat 4R3B1, 118 Route de Narbonne, 31062 Toulouse Cedex, France,...