Experimental Data Snapshot

  • Resolution: 1.80 Å
  • R-Value Free: 0.220 
  • R-Value Work: 0.190 

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Relating structure to thermodynamics: the crystal structures and binding affinity of eight OppA-peptide complexes.

Davies, T.G.Hubbard, R.E.Tame, J.R.

(1999) Protein Sci 8: 1432-1444

  • DOI: https://doi.org/10.1110/ps.8.7.1432
  • Primary Citation of Related Structures:  
    1B0H, 1B1H, 1B2H, 1B3H, 1B4H, 1B5H, 1B6H, 1B7H

  • PubMed Abstract: 

    The oligopeptide-binding protein OppA provides a useful model system for studying the physical chemistry underlying noncovalent interactions since it binds a variety of readily synthesized ligands. We have studied the binding of eight closely related tripeptides of the type Lysine-X-Lysine, where X is an abnormal amino acid, by isothermal titration calorimetry (ITC) and X-ray crystallography. The tripeptides fall into three series of ligands, which have been designed to examine the effects of small changes to the central side chain. Three ligands have a primary amine as the second side chain, two have a straight alkane chain, and three have ring systems. The results have revealed a definite preference for the binding of hydrophobic residues over the positively charged side chains, the latter binding only weakly due to unfavorable enthalpic effects. Within the series of positively charged groups, a point of lowest affinity has been identified and this is proposed to arise from unfavorable electrostatic interactions in the pocket, including the disruption of a key salt bridge. Marked entropy-enthalpy compensation is found across the series, and some of the difficulties in designing tightly binding ligands have been highlighted.

  • Organizational Affiliation

    Department of Chemistry, University of York, Heslington, United Kingdom.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
PROTEIN (OLIGO-PEPTIDE BINDING PROTEIN)517Salmonella enterica subsp. enterica serovar TyphimuriumMutation(s): 0 
Find proteins for P06202 (Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720))
Explore P06202 
Go to UniProtKB:  P06202
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP06202
Sequence Annotations
  • Reference Sequence

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Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
PROTEIN (LYS HPE LYS)3N/AMutation(s): 0 
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 1.80 Å
  • R-Value Free: 0.220 
  • R-Value Work: 0.190 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 109.722α = 90
b = 75.953β = 90
c = 70.424γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALAdata scaling
CCP4data scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1998-11-18
    Type: Initial release
  • Version 1.1: 2008-04-26
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2023-12-27
    Changes: Data collection, Database references, Derived calculations