Table 1.

Electrostatic calculations for Na⁺- and K⁺-binding sites in EAAT3. (Sites 1–4 refer to potential cation-binding sites within 10 Å of the amino acid-binding site for the EAAT3 homology models and the Glt_Ph X-ray crystal structures. The EAAT3 and Glt_Ph models used for the valence calculations are in either the HP2-loop open or HP2-loop closed conformations and either the substrate-bound (glutamate or aspartate) or apo form.)

	site 1	site 2	site 3	site 4
EAAT3
sodium
EAAT3wt|open|apo	0.80	<0.3	0.72	0.84
EAAT3wt|open|l-glu	0.80	<0.3	0.72	<0.3
EAAT3wt|closed|apo	1.04	0.93	0.62	0.97
EAAT3wt|occluded|l-glu	1.04	0.93	0.91	<0.3
thallium
EAAT3wt|open|apo	0.91	<0.3	<0.3	0.56
EAAT3wt|closed|apo	0.80	0.84	<0.3	0.94
EAAT3wt|occluded|l-glu	0.78	0.79	<0.3	<0.3
potassium
EAAT3wt|open|apo	1.16	<0.3	<0.3	1.11
EAAT3wt|open|l-glu	1.16	<0.3	<0.3	<0.3
EAAT3wt|closed|apo	1.13	1.21	0.87	1.44
EAAT3wt|occluded|l-glu	1.13	1.21	<0.3	<0.3
caesium
EAAT3wt|open|apo	1.03	<0.3	<0.3	0.90
EAAT3wt|closed|apo	0.71	0.83	<0.3	1.07
EAAT3wt|occluded|l-glu	0.71	0.83	<0.3	<0.3
GltPh
sodium
GltPh|open|apo	1.27	0.56	0.91	0.81
GltPh|open|l-asp	1.27	0.56	0.91	<0.3
GltPh|occluded|l-asp	1.05	1.05	0.61	<0.3
thallium
GltPh|open|TBOA	1.09	0.46	<0.3	<0.3
GltPh|occluded|l-asp	1.07	1.08	<0.3	<0.3