Despite its importance in plant metabolism, no sequences of higher plant ATP-dependent phosphofructokinase (EC ) are annotated in the databases. We have purified the enzyme from spinach leaves 309-fold to electrophoretic homogeneity. The purified enzyme was a homotetramer of 52 kDa subunits with a specific activity of 600 mUÆmg )1 and aKmvalue for ATP of 81 lm.