Crystallisation and structure determination. Freshly purified PfCLK3 kinase domain was concentrated to 6.8 mg/mL, incubated with 0.5 mM TCMDC-135051 for 1 hour before centrifuging and setting up crystal trays. Crystals grew at 4 °C in a condition containing 2 M ammonium sulphate, 0.2 M potassium sodium tartrate tetrahydrate and 0.1 M sodium citrate pH 5.6. Crystals were cryo-protected in the reservoir solution supplemented with 10% v/v ethylene glycol and 10% v/v glycerol before flash freezing in liquid nitrogen.