Pyruvate, phosphate dikinase (PPDK)

Pyruvate, phosphate dikinase (PPDK) is a multi-domain enzyme that catalyzes the reversible conversion of ATP, inorganic phosphate, and pyruvate into phosphoenolpyruvate (PEP), AMP, and diphosphate. It operates using a mechanism in which a central histidine residue (His455) physically shuttles phosphoryl groups between two separate catalytic centers on the enzyme by a large swiveling domain motion. PPDK plays a crucial biochemical role in C4 and CAM photosynthetic pathways in plants—performing the ATP-consuming step that helps concentrate CO2 for Rubisco function—and in gluconeogenesis and ATP generation in various microorganisms. The enzyme is comprised of three main structural domains (N-terminal ATP/phosphate-binding, central histidine carrier, and C-terminal PEP/pyruvate-binding). Despite its essential roles in plant and microbial metabolism, PPDK is not a common target for approved drugs, and research focuses mainly on plant biotechnology, metabolic engineering, and basic biochemistry[1][2][3][4][5][6][7][8][9][10].

Other names

ATP:pyruvate, phosphate phosphotransferasePyruvate, orthophosphate dikinasePyruvate phosphate dikinasePPDK

Catalyzes the reversible reaction: pyruvate + phosphate + ATP ⇌ phosphoenolpyruvate + AMP + diphosphate + H(+). Swiveling domain mechanism: the enzyme uses a central histidine residue (His455) to shuttle a phosphoryl group between distinct active sites on the enzyme by large domain motions. Inhibitors such as phosphonopyruvate act by occupying the PEP binding site and blocking catalysis.