Plasmodium falciparum DDX3X is a nucleocytoplasmic protein and requires N-terminal for DNA helicase activity

Malaria is a haemato-protozoan disease which causes thousands of deaths every year. Due to the alarming increase of drug resistant strains of P. falciparum, malaria is now becoming more deadly. Helicases are the most important components of the cellular machinery without which cells are unable to survive. The importance of helicases has been proven in variety of organisms. In this study we have reported detailed biochemical characterization of human homologue of DDX3X from Plasmodium falciparum (PfDDX3X). Our study revealed that PfDDX3X is ATP- dependent DNA helicase whereas in human host it is ATP-dependent RNA helicase. We show that N-terminal is essential for its activity and it is present in nucleus and cytoplasm in intraerythrocytic developmental stages of P. falciparum 3D7 strain. Also, it is highly expressed in the schizont stage of P. falciparum 3D7strain. The present study suggests that a protein can perform different functions in different systems. The present study will help to understand the basic biology of malaria parasite P. falciparum.