E3 ubiquitin-protein ligase involved in the regulation of organ and seed size. Probably functions to restrict cell proliferation during organ and seed development. S-ubiquitinyl-[E2 ubiquitin-conjugating enzyme]-L-cysteine + [acceptor protein]-L-lysine = [E2 ubiquitin-conjugating enzyme]-L-cysteine + N(6)-ubiquitinyl-[acceptor protein]-L-lysine. Protein modification; protein ubiquitination. Plants overexpressing DA2L exhibit reduced organ size, biomass, and seed size and weight.