Fig. 2: The dual receptor sites for BTX-B in rNaV1.5c.

a Side view of the structure of rNaV1.5c with BTX-B Site IIB2 (cyan) located in the fenestration between the DIII (dark yellow) and DIV (dark red) interface, and Site IIB2 (bright green) in the fenestration between the DI (dark blue) and DIV (dark red) interface. b Top view of the structure of rNaV1.5c with BTX-B Sites IIB1 and IIB2. The two BTX-B molecules are ~7 Å apart. c Cryo-EM density map (black mesh, 3.5σ) of Site IIB2 (cyan). d Cryo-EM density map (black mesh, 3.5σ) of Site IIB1 (bright green).