Pyridoxal kinases (PdxK) catalyze the phosphorylation of vitamin B6 precursors. Thus, these enzymes are an essential part of many metabolic processes in all organisms. The protozoan parasite Plasmodium falciparum (the main causative agent of Malaria tropica) possesses a unique de novo B6-biosynthesis pathway in addition to a interconversion pathway based on the activity of plasmodial PdxK (PfPdxK). The role of PdxK in B6 salvage has prompted previous authors to suggest PdxK as a promising target for structure-based antimalarial drug design. Here, the expression, purification, crystallization and preliminary X-ray diffraction analysis of PfPdxK are reported. PfPdxK crystals have been grown in space group P2₁, with unit-cell parameters a=52.7, b=62.0, c=93.7 Å, β=95°. A data set has been collected to 2 Å resolution and an initial molecular-replacement solution is described.
Keywords: Plasmodium falciparum; malaria; pyridoxal kinase; vitamin B6 biosynthesis and salvage.