Apicomplexans cause deadly diseases like malaria (Plasmodium sp.) and toxoplasmosis (Toxoplasma sp.). These parasites affect over 200 million people worldwide each year. Our interest lies in understanding how apicomplexans carry out DNA transactions within the context of their host – specifically how these processes occur in an organelle called the 'apicoplast'. To answer this question we use electron cryomicroscopy, fast enzyme kinetics, next generation DNA sequencing and associated biochemical and biophysical techniques.