Deciphering the 3D Structure and Function of Phosphofructokinase from Fission Yeast

Glycolysis is an essential process for the energy metabolism of living cells and is tightly regulated during the cell cycle. A main regulatory step is centered around the behavior of phosphofructokinase (PFK), which catalyzes the phosphorylation of fructose-6-phosphate (F6P) to fructose-1,6-bisphosphate and represents the first irreversible step specific for glycolysis. PFK is ubiquitously expressed in all cellular organisms; however, the subunit composition, oligomerization state, and specific kinetic behavior of this enzyme are species and tissue dependent. While in prokaryotes, PFK is a homo-tetramer composed of identical subunits with a molecular mass of 35 kDa each, in the methylotrophic yeast, Pichia pastoris, PFK (PpPFK) is a dodecamer composed of four α-, four βand four γ-subunits [1]. In addition, the eukaryotic enzymes exhibit a much more complex regulatory mechanism than their prokaryotic counterparts with more than 20 allosteric effectors regulating their activity [2].