Purification, crystallization and preliminary X-ray diffraction studies on pyruvate phosphate dikinase from maize

Pyruvate phosphate dikinase (PPDK) from maize catalyzes the reversible conversion of ATP, orthophosphate and pyruvate to AMP, pyrophosphate and PEP. In higher plants, this enzyme is believed to be involved in the C₄ dicarboxylic acid pathway. PPDK was crystallized by the vapour-diffusion method using polyethylene glycol as a precipitant. The crystals belong to the orthorhombic space group C2, with unit-cell parameters a = 108.2, b = 100.2, c = 108.4 Å, β = 96.5°, and diffract to 2.3 Å using SPring-8 synchrotron radiation.