2nww: Difference between revisions

Revision as of 19:11, 21 February 2008

Crystal structure of GltPh in complex with TBOA

OverviewOverview

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 StructureAbout this Structure

2NWW is a Single protein structure of sequence from Pyrococcus horikoshii with as ligand. Full crystallographic information is available from OCA.

ReferenceReference

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

Page seeded by OCA on Thu Feb 21 18:11:56 2008

Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

OCA

@@ Line 4: / Line 4: @@
 ==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.
+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==
@@ Line 25: / Line 25: @@
 [[Category: transmembrane transporter]]
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Tue Jan 29 21:01:09 2008''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 18:11:56 2008''