Quaternary structure of DAPDC enzymes in the crystal form. The asymmetric units of A, Ec-DAPDC (PDB code 1KO0); B, Vc-DAPDC (PDB code 3N2B); C, Mt-DAPDC dimer (PDB code 1HKV); and D, Mt-DAPDC tetramer (PDB code 2O0T) are displayed. The in solution assemblies calculated by PISA are shown for E, Ec-DAPDC (PDB code 1KO0), F, Mt-DAPDC (PDB code 1HKV and 2O0T); and G, Vc-DAPDC (PDB code 3N2B).