Catalyzes the covalent attachment of ubiquitin to other proteins (By similarity). Mediates the selective degradation of short-lived and abnormal proteins (PubMed:16628214). 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). Required, cell autonomously, for death of the linker cell, a male-specific cell which guides the elongation of the gonad; perhaps acting as part of the ubiquitin proteasome system (UPS) and modulated by heat shock transcription factor hsf-1 (PubMed:26952214). S-ubiquitinyl-[E1 ubiquitin-activating enzyme]-L-cysteine + [E2 ubiquitin-conjugating enzyme]-L-cysteine = [E1 ubiquitin-activating enzyme]-L-cysteine + S-ubiquitinyl-[E2 ubiquitin-conjugating enzyme]-L-cysteine. Protein modification; protein ubiquitination. Interacts with the brc-1-brd-1 heterodimer following ionizing irradiation. Expressed in the nervous system. Expressed at all stages of development (PubMed:8441382, PubMed:8670823). Expressed in most embryonic tissues and larval tissues at the early stages (PubMed:8670823). Highly expressed in neurons, pharynx, the hyperdermis and body muscles in L1, L2, L3 and dauer larvae (PubMed:8670823). From the L4 stage of larval development and in adults, expression is mainly restricted to the nervous system, but is also expressed in the pharynx and hyperdermis (PubMed:8670823). Expressed in the linker cell, a male-specific cell which guides the elongation of the gonad, about 1-2 hours before induction of linker cell death (PubMed:26952214). RNAi-mediated knockdown results in reduced ubiquitination at DNA damage sites (PubMed:16628214). Inappropriate survival of male gonadal linker cell (PubMed:26952214). Belongs to the ubiquitin-conjugating enzyme family.