Crystal structures of an E1–E2–ubiquitin thioester mimetic reveal molecular mechanisms of transthioesterification

Abstract

The molecular mechanism of ubiquitin transfer from E1 to E2 enzymes is still unclear. By solving the crystal structure of a covalently trapped E1–E2–ubiquitin thioester mimetic, the authors identify two conformations of this complex which suggest an affinity switch mechanism for thioester transfer.