This proposal gathers Principal investigators from French Institutions that use cryo-EM to unravel the molecular mechanisms associated with various biological processes. Scientists belong to 8 centres that currently use Cryo-EM and have already used ESRF CM01 beamline. All the PIs in this application have already used CM01 during the past 2 years. Projects include the study of bacterial secretion systems (Bordeaux, Lyon, Paris), viruses and their infection mechanisms (Marseille), translation and its control (Bordeaux, Toulouse, Paris, Strasbourg), transcription (Strasbourg, Paris) and Macromolecular transport (Bordeaux, Lyon, Strasbourg). Note that there is been a change of PI at the Montpelliier center, with G; Labesse replacing P. Bon as a PI.