3KFJ

Crystal Structure of the Grb2 SH2 Domain in Complex with a Flexible Ac-pY-E-N-NH2 Tripeptide Mimic


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.02 Å
  • R-Value Free: 0.230 
  • R-Value Work: 0.198 

Starting Model: experimental
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This is version 1.3 of the entry. See complete history


Literature

Thermodynamic and structural effects of conformational constraints in protein-ligand interactions. Entropic paradoxy associated with ligand preorganization.

DeLorbe, J.E.Clements, J.H.Teresk, M.G.Benfield, A.P.Plake, H.R.Millspaugh, L.E.Martin, S.F.

(2009) J Am Chem Soc 131: 16758-16770

  • DOI: https://doi.org/10.1021/ja904698q
  • Primary Citation of Related Structures:  
    3IMD, 3IMJ, 3IN7, 3IN8, 3KFJ

  • PubMed Abstract: 

    Succinate- and cyclopropane-derived phosphotyrosine (pY) replacements were incorporated into a series of Grb2 SH2 binding ligands wherein the pY+1 residue was varied to determine explicitly how variations in ligand preorganization affect binding energetics and structure. The complexes of these ligands with the Grb2 SH2 domain were examined in a series of thermodynamic and structural investigations using isothermal titration calorimetry and X-ray crystallography. The binding enthalpies for all ligands were favorable, and although binding entropies for all ligands having a hydrophobic residue at the pY+1 site were favorable, binding entropies for those having a hydrophilic residue at this site were unfavorable. Preorganized ligands generally bound with more favorable Gibbs energies than their flexible controls, but this increased affinity was the consequence of relatively more favorable binding enthalpies. Unexpectedly, binding entropies of the constrained ligands were uniformly disfavored relative to their flexible controls, demonstrating that the widely held belief that ligand preorganization should result in an entropic advantage is not necessarily true. Crystallographic studies of complexes of several flexible and constrained ligands having the same amino acid at the pY+1 position revealed extensive similarities, but there were some notable differences. There are a greater number of direct polar contacts in complexes of the constrained ligands that correlate qualitatively with their more favorable binding enthalpies and Gibbs energies. There are more single water-mediated contacts between the domain and the flexible ligand of each pair; although fixing water molecules at a protein-ligand interface is commonly viewed as entropically unfavorable, entropies for forming these complexes are favored relative to those of their constrained counterparts. Crystallographic b-factors in the complexes of constrained ligands are greater than those of their flexible counterparts, an observation that seems inconsistent with our finding that entropies for forming complexes of flexible ligands are relatively more favorable. This systematic study highlights the profound challenges and complexities associated with predicting how structural changes in a ligand will affect enthalpies, entropies, and structure in protein-ligand interactions.


  • Organizational Affiliation

    Department of Chemistry and Biochemistry, The Institute of Cellular and Molecular Biology, University of Texas, Austin, Texas 78712, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Growth factor receptor-bound protein 2117Homo sapiensMutation(s): 0 
Gene Names: GRB2ASH
UniProt & NIH Common Fund Data Resources
Find proteins for P62993 (Homo sapiens)
Explore P62993 
Go to UniProtKB:  P62993
PHAROS:  P62993
GTEx:  ENSG00000177885 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP62993
Sequence Annotations
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  • Reference Sequence
Biologically Interesting Molecules (External Reference) 1 Unique
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.02 Å
  • R-Value Free: 0.230 
  • R-Value Work: 0.198 
  • Space Group: P 43 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 41.873α = 90
b = 41.873β = 90
c = 108.811γ = 90
Software Package:
Software NamePurpose
CrystalCleardata collection
MOLREPphasing
CNSrefinement
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

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Ligand Structure Quality Assessment 


Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2010-03-02
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Atomic model, Database references, Derived calculations, Non-polymer description, Structure summary, Version format compliance
  • Version 1.2: 2012-12-12
    Changes: Other
  • Version 1.3: 2023-09-06
    Changes: Data collection, Database references, Derived calculations, Refinement description