Résumé
SUMOylation is involved in the regulation of many cellular processes, in particular gene expression regulation and is related to various human diseases: neurological disorders (Alzheimer, Parkinson, Huntington), metabolic disorders (diabetes), response to both viral and bacterial infections and cancer (Flotho & Melchior, 2013). The sumoylation pathway is a reversible enzymatic process carried out through ATP-dependent enzymatic cascade. E1 and E2 are the first two enzymes in the cascade. E1 is a hetero-dimer (SAE1/SAE2) that catalyzessequential adenylation and thioesterification reactions, but the conformational properties of this enzyme are not fully understood. Two X-ray crystallographic structures have been obtained for E1, displaying significantly different units, but the reason for these differences in crystallogenesis remains mysterious, especially since the structures of SAE1 and SAE2 are quite similar in both structures. In the present project, we intend to analyze the internal dynamics as well as the allosteric pathways of E1 complex for both crystallographic structures. Thevariations of the pathways for these more or less connected organizations will be compared.