Expression, purification, electron microscopy, N-glycosylation mutagenesis and molecular modeling of human P2X4 and Dictyostelium discoideum P2XA

► We expressed human P2X4 and Dictyostelium discoideum (Dd) P2XA in Sf9 insect cells. ► Both receptors were capable of binding to ATP-coupled sepharose beads. ► Preparative electrophoresis was used to purify DdP2XA trimers. ► We determined a 21 Å-resolution structure of DdP2XA using single particle analysis. ► DdP2XA cannot be modeled accurately using the zebrafish P2X4 crystal structure.