Figure 4. Voltage dependent gating of CNGA1 E365Q mutant.
(A) Sample traces and I-V curves of voltage activation of CNGA1 E365Q mutant. Whole cell currents were recorded with 1 mM cGMP in the pipette (cytosolic). I-V curves were obtained from the peak currents at various activation potentials. Data points are mean ± SEM (n=5 independent experiments).
(B) Down view (left) of Q365 in conformation 1 with EM density map contoured at 5.0 σ and side view (right) of the mutant filter (green) in comparison with the wide-type filter (yellow). Inset: H-bonds between Q365 side chain and carbonyls of two neighboring I363s.
(C) Down view (left) of Q365 in conformation 2 and side view (right) of the mutant filter in comparison with the wide-type filter (right). The mutant filter is conductive in this conformation.
