Ubiquitin-Conjugating Enzyme E2 D4 (UBE2D4) is a ligase that belongs to the Ubiquitin-Conjugating Enzyme family. UBE2D4 has been proposed to participate in Ubl conjugation pathway. UBE2D4 takes part in post-translational protein modification, protein K6-linked ubiquitination, protein K11-linked ubiquitination, protein K27-linked ubiquitination, protein K29-linked ubiquitination, protein K48-linked ubiquitination, and protein K63-linked ubiquitination. UBE2D4 regulate of protein metabolic process. UBE2D4 accepts ubiquitin from the E1 complex and catalyzes its covalent attachment to other proteins. In vitro, UBE2D4 able to promote polyubiquitination using all 7 ubiquitin Lys residues, but may prefer 'Lys-11' and 'Lys-48'-linked poly-ubiquitination.