2nwl | pdb_00002nwl
Crystal structure of GltPh in complex with L-Asp
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| 2nwl, resolution 2.960Å | |||||||||||||
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| Ligands: | ASP and PLM | ||||||||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||||||||
Overview
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.
About this Structure
2NWL is a Single protein structure of sequence from Pyrococcus horikoshii. Full crystallographic information is available from OCA.
Reference
Coupling substrate and ion binding to extracellular gate of a sodium-dependent aspartate transporter., Boudker O, Ryan RM, Yernool D, Shimamoto K, Gouaux E, Nature. 2007 Jan 25;445(7126):387-93. Epub 2007 Jan 17. PMID:17230192
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