2XQ2

Structure of the K294A mutant of vSGLT


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.73 Å
  • R-Value Free: 0.274 
  • R-Value Work: 0.251 
  • R-Value Observed: 0.252 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

The Mechanism of Sodium and Substrate Release from the Binding Pocket of Vsglt

Watanabe, A.Choe, S.Chaptal, V.Rosenberg, J.M.Wright, E.M.Grabe, M.Abramson, J.

(2010) Nature 468: 988

  • DOI: 10.1038/nature09580
  • Primary Citation of Related Structures:  
    2XQ2

  • PubMed Abstract: 
  • Membrane co-transport proteins that use a five-helix inverted repeat motif have recently emerged as one of the largest structural classes of secondary active transporters. However, despite many structural advances there is no clear evidence of how ion and substrate transport are coupled ...

    Membrane co-transport proteins that use a five-helix inverted repeat motif have recently emerged as one of the largest structural classes of secondary active transporters. However, despite many structural advances there is no clear evidence of how ion and substrate transport are coupled. Here we report a comprehensive study of the sodium/galactose transporter from Vibrio parahaemolyticus (vSGLT), consisting of molecular dynamics simulations, biochemical characterization and a new crystal structure of the inward-open conformation at a resolution of 2.7 Å. Our data show that sodium exit causes a reorientation of transmembrane helix 1 that opens an inner gate required for substrate exit, and also triggers minor rigid-body movements in two sets of transmembrane helical bundles. This cascade of events, initiated by sodium release, ensures proper timing of ion and substrate release. Once set in motion, these molecular changes weaken substrate binding to the transporter and allow galactose readily to enter the intracellular space. Additionally, we identify an allosteric pathway between the sodium-binding sites, the unwound portion of transmembrane helix 1 and the substrate-binding site that is essential in the coupling of co-transport.


    Organizational Affiliation

    Department of Physiology, University of California, Los Angeles, Los Angeles, California 90095-1759, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
SODIUM/GLUCOSE COTRANSPORTERA593Vibrio parahaemolyticusMutation(s): 3 
Gene Names: sglT
Membrane Entity: Yes 
UniProt
Find proteins for P96169 (Vibrio parahaemolyticus)
Explore P96169 
Go to UniProtKB:  P96169
Protein Feature View
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
SODIUM/GLUCOSE COTRANSPORTERB593Vibrio parahaemolyticusMutation(s): 3 
Gene Names: sglT
Membrane Entity: Yes 
UniProt
Find proteins for P96169 (Vibrio parahaemolyticus)
Explore P96169 
Go to UniProtKB:  P96169
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
PEG
Query on PEG

Download Ideal Coordinates CCD File 
C [auth A], D [auth A], E [auth A]DI(HYDROXYETHYL)ETHER
C4 H10 O3
MTHSVFCYNBDYFN-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.73 Å
  • R-Value Free: 0.274 
  • R-Value Work: 0.251 
  • R-Value Observed: 0.252 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 85.3α = 90
b = 112.68β = 90
c = 238.77γ = 90
Software Package:
Software NamePurpose
BUSTERrefinement
HKL-2000data reduction
HKL-2000data scaling
PHASERphasing

Structure Validation

View Full Validation Report




Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2010-12-08
    Type: Initial release
  • Version 1.1: 2011-08-10
    Changes: Database references, Version format compliance