Table 2. Coordination of the K⁺ Ion at S4 by the Carbonyl and Side-Chain Oxygens of T480^a.

distance	WT Kv1.5	Kv1.5[D469E]	Kv1.5[P488S]	Kv1.5[T527M]
K+–O (A)	2.78 ± 0.19	3.83 ± 0.38	3.75 ± 0.48	3.80 ± 0.65
K+–O (B)	2.91 ± 0.41	3.84 ± 0.49	3.74 ± 0.51	3.81 ± 0.45
K+–O (C)	2.85 ± 0.23	3.83 ± 0.41	3.75 ± 0.49	3.79 ± 0.95
K+–O (D)	2.94 ± 0.33	3.84 ± 0.51	3.74 ± 0.43	3.81 ± 0.38
K+–OH (A)	2.85 ± 0.31	2.73 ± 0.11	2.67 ± 0.23	2.75 ± 0.27
K+–OH (B)	3.07 ± 0.34	2.74 ± 0.21	2.66 ± 0.51	2.76 ± 0.31
K+–OH (C)	3.03 ± 0.34	2.73 ± 0.12	2.67 ± 0.12	2.75 ± 0.29
K+–OH (D)	3.05 ± 0.24	2.74 ± 0.19	2.66 ± 0.19	2.76 ± 0.34
K+–O (H2O)	2.82–3.64	2.64–3.17	2.64–3.17	2.64–3.17

^aThe average K⁺–O distances obtained from the last 30 ns of MD simulations for each channel are listed (in Å). A water molecule from the cavity is in the coordination shell, but because of frequent exchanges with cavity waters, only a range can be given.