Transcription factor-like protein that binds to specific DNA motifs called ub-HS-motif associated with several locations where proteins other than histone H2B are ubiquitinated (ub-hotspots) (PubMed:31015336). Ubiquitination at these sites depends on the SUMO-targeted ubiquitin ligase (STUbL) complex SLX5/SLX8 and protein turnover on the CDC48 segregase (PubMed:31015336). UBC9, SIZ1, or SIZ2 sumoylate DNA-bound EUC1 to stabilize its DNA-binding (PubMed:31015336). Sumoylated EUC1 acts a cofactor required for the recruitment of the SLX5/SLX8 STUbL complex via specific contacts between EUC1 and SLX5, as well as an additional SUMO-mediated interaction (PubMed:31015336). SLX5/SLX8 then ubiquitinates EUC1 and presumably other targets at ub-hotspots, and the CDC48/UFD1/NPL4 complex, together with UBX4 and UBX5, removes Lys-48-linked ubiquitinated proteins from chromatin. Ubiquitinated proteins could be either degraded by the proteasome or recycled by deubiquitination (PubMed:31015336). EUC1 itself does not seem to underlie extensive turnover, as it is a very stable protein (PubMed:31015336). EUC1 is able to act as a transcription factor, but its function at ub-hotspots does not seem to depend on this ability (PubMed:31015336). EUC1-mediated ub-hotspots are crucial during stress responses when gene expression control is impaired (PubMed:31015336). Homodimer (PubMed:31015336). Interacts with SLX5 (PubMed:31015336). Localizes to few distinct genomic hotspots where proteins other than histone H2B are ubiquitinated (ub-hotspots). The coiled-coil motif is required for homodimerization. Sumoylated at Lys-231 and subsequently ubiquitinated by the SUMO-targeted ubiquitin ligase (STUbL) complex SLX5/SLX8. Prevents ub-hotspot formation and exacerbates heat sensitivity of cells deficient in Rpd3L histone deacetylase complex members (PubMed:31015336). Leads to the up-regulation of the expression of the Rpd3S complex subunit RCO1 of the Rpd3S complex and down-regulation of HSP12 and SIR2 (PubMed:31015336). Present with 238 molecules/cell in log phase SD medium.