Figure 6. Structures of ions-only bound transport domain.

(A) Superimposition of the fully bound transport domains (grey) and Tl⁺-bound Glt_Phⁱⁿ transport domain in the bound-like conformation (colors), with the averaged anomalous difference Fourier map contoured at 8σ (cyan mesh). (B) Superimposition of the fully bound (grey) and Na⁺-only bound Glt_Ph-R397A (colors) transport domains. (C) Na⁺ and L-asp binding sites with fully-bound structure shown in white and Na⁺-bound structure in colors. Hinge glycine residues are shown as spheres. The modeled Na⁺ ion in Na1 site is pink. (D) Superimposition of the HP2-TM8 in the fully bound transport domain (grey) and in Glt_Ph-R397A bound to Na⁺ only (colors), showing similar conformations of HP2a. (E) WebLogo representation of the consensus sequence and relative abundance of residues in HP2 tip. (F) Surface representation of the transport domain of Glt_Ph-R397A bound to Na⁺ only showing access to the substrate-binding site. L-asp was placed into the binding site for reference.

DOI: http://dx.doi.org/10.7554/eLife.02283.016

Figure 6—figure supplement 1. Na⁺ only bound Glt_Ph-R397A.

Stereo view of the averaged 2F_o-F_c electron density map contoured at 1σ around HP1 and HP2.

DOI: http://dx.doi.org/10.7554/eLife.02283.017

Figure 6—figure supplement 2. Superimposition of the transport domains bound to Na⁺ and L-asp (light grey), Na⁺ and L-TBOA (dark grey) and Na⁺ only (colors).

Ligands are omitted for clarity, except that L-TBOA is shown as spheres in the right panel. Nostably, the observed additional opening of HP2 is necessary to accommodate L-TBOA.

DOI: http://dx.doi.org/10.7554/eLife.02283.018

Figure 6—figure supplement 3. Sequence alignment for the HP2 tip region of Glt_Ph and human EAAT sub-types 1–5.

DOI: http://dx.doi.org/10.7554/eLife.02283.019