Ubiquitin-Conjugating Enzyme E2 R2 (UBE2R2) is a modification enzyme that belongs to the ubiquitin-conjugating enzyme family. UBE2R2 is involved in cell growth and transformation. It accepts ubiquitin from the E1 complex and catalyzes its covalent attachment to other proteins. In vitro, UBE2R2 catalyzes monoubiquitination and 'Lys-48'-linked polyubiquitination. It may be involved in degradation of katenin.