Endogenous structure of antimalarial target PfATP4 reveals an apicomplexan-specific P-type ATPase modulator.

The Plasmodium falciparum sodium efflux pump PfATP4 is a leading antimalarial target, but suffers from a lack of high-resolution structural information needed to identify functionally important features in conserved regions and guide rational design of next generation inhibitors. Here, we determine a 3.7 à cryoEM structure of PfATP4 purified from CRISPR-engineered P. falciparum parasites, revealing a previously unknown, apicomplexan-specific binding partner, PfABP, which forms a conserved, likely modulatory interaction with PfATP4. The discovery of PfABP presents an unexplored avenue for designing PfATP4 inhibitors.