Function
Catalyzes the covalent attachment of ubiquitin to other proteins (By similarity). Mediates the selective degradation of short-lived and abnormal proteins. Plays a role in the DNA damage response (PubMed:16628214). In particular, in response to ionizing radiation, associates with the E3 ubiquitin-protein ligase brc-1-brd-1 heterodimer on chromatin to activate E3-ubiquitin ligase activity of the heterodimer, and thus its DNA damage repair mechanisms (PubMed:16628214).