Table 1. GltpH residues identified in our computations to play a functional role and their EAAT1 counterparts

Gltph residue

Structural element

Role inferred from MD (rows 9-10) and ENM (rows 11-12)

EAAT1 counterpart

G354, G357

HP2

Glu recognition, loop flexibility

G442, Q445

S277-S279

HP1

Glu binding (3-Ser motif)

S364-S366           

D312-T314

TM7

Glu coordination (NMDGT motif)

D400-T402

R397-T398

TM8

Stabilization of bound glutamate

R479-T480

T314

TM7                     

 

Water binding

T402

N401, V400

TM8                     

N483, T482

D390, D394

TM8

Pathway for water and Na+ ions entry/exit and Glu stabilization

D472, D476

N310, A307, D312

TM7

 

Na+ binding site I 

N398, A395

D400

N401, G404

TM8

N483, G486

L303, G306

TM7

 

Na+ binding site II

L391,G394

D405

TM8

D487

M286

HP1

Blockers on exit pathway – (delivery to the IC region)

F373

L303

TM7

L391

G144

TM4

Hinge center for global opening/closing of the trimer

E184

L183

TM5

R268

H114

H332

L34

TM7/8 loop

Potential sites for capture of anions from the EC region

K152

E420

Residues implicated in recognition and binding of glutamate, water or Na+ ions, as seen in the simulation analysis. The equivalent residues in EAAT1 are given in the fourth column. Residues highlighted in bold are those which are highly conserved, bold & underlined are those which are both conserved and implicated in the function of transport and/or binding.