Cryo-EM structures reveal the molecular mechanism of SUMO E1-E2 thioester transfer.

ABSTRACT: Post-translational modification of proteins by SUMO (small ubiquitin-like modifier) regulates fundamental cellular processes and occurs through the sequential interactions and activities of three enzymes: E1, E2 and E3. SUMO E1 activates SUMO in a two-step process involving adenylation and thioester bond formation, followed by transfer of SUMO to its dedicated E2 enzyme, UBC9. This process is termed E1-E2 thioester transfer (or transthioesterification). Despite its fundamental importance, the molecular basis for SUMO E1-UBC9 thioester transfer and the molecular rules governing SUMO E1-UBC9 specificity are poorly understood. Here we present cryo-EM reconstructions of human SUMO E1 in complex with UBC9, SUMO1 adenylate and SUMO1 thioester intermediate. Our structures reveal drastic conformat

SUBMITTER: Nayak A 

PROVIDER: S-EPMC12700794 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature