4O3B

Crystal structure of an open/closed glua2 ligand-binding domain dimer at 1.91 A resolution


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.91 Å
  • R-Value Free: 0.178 
  • R-Value Work: 0.138 
  • R-Value Observed: 0.140 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

L-Asp is a useful tool in the purification of the ionotropic glutamate receptor A2 ligand-binding domain.

Krintel, C.Frydenvang, K.Ceravalls de Rabassa, A.Kaern, A.M.Gajhede, M.Pickering, D.S.Kastrup, J.S.

(2014) FEBS J 281: 2422-2430

  • DOI: 10.1111/febs.12795
  • Structures With Same Primary Citation

  • PubMed Abstract: 
  • In purification of the ionotropic glutamate receptor A2 (GluA2) ligand-binding domain (LBD), L-Glu-supplemented buffers have previously been used for protein stabilization during the procedure. This sometimes hampers structural studies of low-affinit ...

    In purification of the ionotropic glutamate receptor A2 (GluA2) ligand-binding domain (LBD), L-Glu-supplemented buffers have previously been used for protein stabilization during the procedure. This sometimes hampers structural studies of low-affinity ligands, because L-Glu is difficult to displace, despite extensive dialysis. Here, we show that L-Asp binds to full-length GluA2 with low affinity (Ki = 0.63 mM) and to the GluA2 LBD with even lower affinity (Ki = 2.6 mM), and we use differential scanning fluorimetry to show that L-Asp is able to stabilize the isolated GluA2 LBD. We also show that L-Asp can replace L-Glu during purification, providing both equal yields and purity of the resulting protein sample. Furthermore, we solved three structures of the GluA2 LBD in the presence of 7.5, 50 and 250 mM L-Asp. Surprisingly, with 7.5 mM L-Asp, the GluA2 LBD crystallized as a mixed dimer, with L-Glu being present in one subunit, and neither L-Asp nor L-Glu being present in the other subunit. Thus, residual L-Glu is retained from the expression medium. On the other hand, only L-Asp was found at the binding site when 50 or 250 mM L-Asp was used for crystallization. The binding mode observed for L-Asp at the GluA2 LBD is very similar to that described for L-Glu. Taking our findings together, we have shown that L-Asp can be used instead of L-Glu for ligand-dependent stabilization of the GluA2 LBD during purification. This will enable structural studies of low-affinity ligands for lead optimization in structure-based drug design.


    Related Citations: 
    • Mechanisms for activation and antagonism of an AMPA-sensitive glutamate receptor: crystal structures of the GluR2 ligand binding core.
      Armstrong, N., Gouaux, E.
      (2000) Neuron 28: 165

    Organizational Affiliation

    Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark.



Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Glutamate receptor 2
A, B
263Rattus norvegicusMutation(s): 0 
Gene Names: Gria2Glur2
Find proteins for P19491 (Rattus norvegicus)
Go to UniProtKB:  P19491
Protein Feature View
  • Reference Sequence
Small Molecules
Ligands 7 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
PG4
Query on PG4

Download CCD File 
B
TETRAETHYLENE GLYCOL
C8 H18 O5
UWHCKJMYHZGTIT-UHFFFAOYSA-N
 Ligand Interaction
GLU
Query on GLU

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B
GLUTAMIC ACID
C5 H9 N O4
WHUUTDBJXJRKMK-VKHMYHEASA-N
 Ligand Interaction
PEG
Query on PEG

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A
DI(HYDROXYETHYL)ETHER
C4 H10 O3
MTHSVFCYNBDYFN-UHFFFAOYSA-N
 Ligand Interaction
SO4
Query on SO4

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A, B
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
GOL
Query on GOL

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A, B
GLYCEROL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
ACT
Query on ACT

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A
ACETATE ION
C2 H3 O2
QTBSBXVTEAMEQO-UHFFFAOYSA-M
 Ligand Interaction
CL
Query on CL

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A
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
GLUKi:  820   nM  Binding MOAD
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.91 Å
  • R-Value Free: 0.178 
  • R-Value Work: 0.138 
  • R-Value Observed: 0.140 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 62.72α = 90
b = 93.72β = 90
c = 97.14γ = 90
Software Package:
Software NamePurpose
PHASERphasing
PHENIXrefinement
PDB_EXTRACTdata extraction
MOSFLMdata reduction
SCALAdata scaling

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2014-04-16
    Type: Initial release
  • Version 1.1: 2014-06-18
    Changes: Database references
  • Version 1.2: 2017-05-31
    Changes: Structure summary
  • Version 1.3: 2018-03-07
    Changes: Data collection