1. Aix-Marseille Univ., CNRS, UMR 7281, Bioenergetics and Protein Engineering, 13402 Marseille, France
2. Univ. Bordeaux, CNRS, Bordeaux INP, UMR 5255, Institute of Molecular Sciences, F-33400 Talence, France
3. Microscopy Facility, CNRS, FR 3479, Mediterranean Institute of Microbiology, 13402 Marseille, France