Extended Data Fig. 10: Structural characterization of CATSPERη and TMEM249.

a, Side view (left) and central slice view (right) of the electron density maps of CATSPERη and the adjacent components. The map was generated in ChimeraX. b, Electron density maps of CATSPERη. The map allows accurate assignment of the side chains of the bulky residues. The densities, shown as blue meshes, are contoured at 4σ in PyMOL. c, Predicted structure of TMEM249 by tFold perfectly fits into the density near CATSPERη with minor adjustments. The structure has the characteristics of two transmembrane helices and a β-sheet (arrows) in the cytosolic domain. d, TMEM249 interacts with CATSPERη and VSD4 in the transmembrane and cytosolic regions, respectively. Unlike CATSPERη, TMEM249 does not interact with the stem domain of CATSPERβ.