Fig. 3

Structural overlap of the N-lobe and C-lobe of CaM bound to Na_V1.4 CTerm. a CaM N-lobes aligned by helices B and C (residues 32–55) show the N-lobe displacement from closed to open upon Ca²⁺ binding (70° of opening). b CaM C-lobes aligned by helices F and G (residues 105–128) show the small conformational change (8° of opening) experienced by the C-lobe upon Ca²⁺ binding; both C-lobes are semi-open (Supplementary Fig. 2). c Close-up of the C-lobe of (Ca²⁺)₄-CaM bound to helix α VI, showing the C-lobe’s EF-hand loop residues (CaM residues 93–104 and 129–140) and the anomalous scattering (F₊ − F₋)e^iφ-calc map at a 4σ contour within 10 Å of either Ca²⁺ ion. d, Close-up of the N-lobe of (Ca²⁺)₄-CaM showing the N-lobe’s EF-hand loop residues (CaM residues 20–31 and 56–67) and the anomalous scattering (F₊ − F₋)^eiφ-calc map at 3.5σ contour within 10 Å of either Ca²⁺ ion