2.2 SQUARE inside PROTEIN p0 inside PROTEIN p1 inside SIMPLE_MOLECULE L_minus_Serine inside SIMPLE_MOLECULE _space_5_space_10_minus_Methylenetetrahydrofolate inside SIMPLE_MOLECULE _space_5_minus_Methyltetrahydrofolate inside SIMPLE_MOLECULE Glycine STATE_TRANSITION _space_5_space_10_minus_Methylenetetrahydrofolate L_minus_Serine c1 c3 c0 STATE_TRANSITION _space_5_space_10_minus_Methylenetetrahydrofolate _space_5_minus_Methyltetrahydrofolate c1 c2