Abstract

Unusual Properties and Functions of Plant Pyruvate, Orthophospate Dikinase

Veronika Hyskova and Helena Ryslava

The pyruvate, orthophosphate dikinase (PPDK, EC 2.7.9.1), crucial plant enzyme in the process of concentrating CO2 for Calvin cycle, catalyzes phosphoenolpyruvate-regeneration phase of the C4 photosynthetic pathway. However plants possess also nonphotosynthetic isoform of PPDK, which functions are less understood, probably due to its low abundance. In all plants, PPDK is located in both cytoplasmic and plastidic compartments. PPDK catalyzes the reversible ATP- and Pi- dependent formation of phosphoenolpyruvate from pyruvate.