2NWL: Crystal Structure Of Gltph In Complex With L-Asp

Secondary transporters are integral membrane proteins that catalyse the movement of substrate molecules across the lipid bilayer by coupling substrate transport to one or more ion gradients, thereby providing a mechanism for the concentrative uptake of substrates. Here we describe crystallographic and thermodynamic studies of Glt(Ph), a sodium (Na+)-coupled aspartate transporter, defining sites for aspartate, two sodium ions and d,l-threo-beta-benzyloxyaspartate, an inhibitor. We further show that helical hairpin 2 is the extracellular gate that controls access of substrate and ions to the internal binding sites. At least two sodium ions bind in close proximity to the substrate and these sodium-binding sites, together with the sodium-binding sites in another sodium-coupled transporter, LeuT, define an unwound alpha-helix as the central element of the ion-binding motif, a motif well suited to the binding of sodium and to participation in conformational changes that accompany ion binding and unbinding during the transport cycle.
PDB ID: 2NWLDownload
MMDB ID: 44626
PDB Deposition Date: 2006/11/15
Updated in MMDB: 2011/10
Experimental Method:
x-ray diffraction
Resolution: 2.96  Å
Source Organism:
Similar Structures:
Biological Unit for 2NWL: trimeric; determined by author and by software (PISA)
Molecular Components in 2NWL
Label Count Molecule
Proteins (3 molecules)
Glutamate Symport Protein
Molecule annotation
Chemicals (6 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB