Ubiquitin-conjugating enzyme E2 W (UBE2W)

Accepts ubiquitin from the E1 complex and catalyzes its covalent attachment to other proteins (PubMed:20061386). Especially monoubiquitinates the N-terminus of various substrates, such as ATXN3, MAPT/TAU, POLR2H/RPB8 and STUB1/CHIP, by recognizing backbone atoms of disordered N-termini (PubMed:23560854, PubMed:23696636, PubMed:25436519).

Involved in degradation of misfolded chaperone substrates by mediating monoubiquitination of STUB1/CHIP, resulting in recruitment of ATXN3 into monoubiquitinated STUB1/CHIP, and limitation of the period of ubiquitin chain attached to STUB1/CHIP substrates by ATXN3. After UV irradiation, but not after mitomycin-C (MMC) treatment, acts as a specific E2 ubiquitin-conjugating receptor to the Fanconi anemia complex by associating with E3 ubiquitin-protein ligase FANCL and catalyzing monoubiquitination of FANCD2, an integral step in the DNA damage pathway (PubMed:19111657, PubMed:21229326).