. "\"Catalysis of ATP-dependent isopeptide bond formation between the carboxy-terminal glycine residues of the small ubiquitin-related modifier SUMO and a substrate lysine residue, leading to the formation of predominately monosumoylated proteins with modified function.\" [GOC:rn, PMID:11031248, PMID:11265250]" . . "SUMO ligase activity" . "SMT3 conjugating enzyme" . "SUMO conjugating enzyme activity" . .