Structural analysis of UNC79 and UNC80 homologues from animals and other eukaryotes. (A) Cryo-EM structure of the human NALCN channel complexed with the subunit FAM155A and the cytoplasmic subunits UNC79 and UC80 (PDB accession number 7SX4). (B) Structural superimposition of the human NALCN complex (in semitransparent white) with the predicted structure of the UNC79/UNC80 dimer from the early-diverging metazoan T. adhaerens. (C) Structural superimposition of the human NALCN complex with the predicted structure of the UNC79/UNC80 dimer from the fungal species C. neoformans. (D) Structural superimposition of human NALCN complex with the predicted structure of the UNC79/UNC80 dimer from the fungal species R. irregularis. (E) Structural superimposition of the human NALCN complex with the predicted structure of the UNC79/UNC80 dimer from the apusomonad T. trahens. (F) Structural superimposition of the human NALCN complex with the predicted structure of the UNC79/UNC80 dimer from the malawimonad G. okellyi. (G) Predicted structure of the UNC79/UNC80 dimer from the Discoba species S. incarcerata. The legend in the lower right indicates relevant taxonomic groupings. For all panels, the labels NT and CT denote the rough location of the N and C termini of UNC79 and UNC80 proteins, respectively, along a horizontal plane. Versions of these predicted structures, colored according to pLDDT confidence scores, are provided in Fig. S6 B.