Aliases: YER125W, RSP5, MDP1, MUT2, NPI1, SMM1, UBY1
Ubiquitin-protein ligase involved in ubiquitin-mediated protein degradation; functions in multivesicular body sorting, heat shock response and ubiquitylation of arrested RNAPII; contains a hect (homologous to E6-AP carboxyl terminus) domain