Figure 3. Ion binding profile in the selectivity filter of CNGA1.
Shown are electron density maps of filter ions in the structures of the cGMP-bound open and apo closed CNGA1 in various salt conditions. All maps are scaled and contoured at 7 σ.
(A) Open CNGA1 in 150 mM KCl and 1 mM CaCl2.
(B) Closed CNGA1 in 150 mM KCl and 1 mM CaCl2.
(C) Open CNGA1 in 150 mM NaCl.
(D) Open CNGA1 in 150 mM NaCl and 1 mM CaCl2.
(E) Open CNGA1 E365Q mutant in 150 mM NaCl and 1 mM CaCl2.
