1. C.E.A./Cadarache-DSV-DEVM-Laboratoire de Bioénergétique Cellulaire, 13108 Saint-Paul-lez-Durance Cedex, France, Department of Biology, Tokyo Metropolitan University, Minamiohsawa 1−1, Hachioji, Tokyo 192-0397, Japan, LSMP, CEA/CNRS, Institut de Biologie Structurale, 41, avenue Jules-Horowitz, 38027 Grenoble Cedex, France.