Experimental Data Snapshot

  • Resolution: 2.30 Å
  • R-Value Free: 0.289 
  • R-Value Work: 0.203 
  • R-Value Observed: 0.203 

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The crystal structure of glutamine-binding protein from Escherichia coli.

Hsiao, C.D.Sun, Y.J.Rose, J.Wang, B.C.

(1996) J Mol Biol 262: 225-242

  • DOI: https://doi.org/10.1006/jmbi.1996.0509
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    The crystal structure of the glutamine-binding protein (GlnBP) from Escherichia coli in a ligand-free "open" conformational state has been determined by isomorphous replacement methods and refined to an R-value of 21.4% at 2.3 A resolution. There are two molecules in the asymmetric unit, related by pseudo 4-fold screw symmetry. The refined model consists of 3587 non-hydrogen atoms from 440 residues (two monomers), and 159 water molecules. The structure has root-mean-square deviations of 0.013 A from "ideal" bond lengths and 1.5 degrees from "ideal" bond angles. The GlnBP molecule has overall dimensions of approximately 60 A x 40 A x 35 A and is made up of two domains (termed large and small), which exhibit a similar supersecondary structure, linked by two antiparallel beta-strands. The small domain contains three alpha-helices and four parallel and one antiparallel beta-strands. The large domain is similar to the small domain but contains two additional alpha-helices and three more short antiparallel beta-strands. A comparison of the secondary structural motifs of GlnBP with those of other periplasmic binding proteins is discussed. A model of the "closed form" GlnBP-Gln complex has been proposed based on the crystal structures of the histidine-binding protein-His complex and "open form" GlnBP. This model has been successfully used as a search model in the crystal structure determination of the "closed form" GlnBP-Gln complex by molecular replacement methods. The model agrees remarkably well with the crystal structure of the Gln-GlnBP complex with root-mean-square deviation of 1.29 A. Our study shows that, at least in our case, it is possible to predict one conformational state of a periplasmic binding protein from another conformational state of the protein. The glutamine-binding pockets of the model and the crystal structure are compared and the modeling technique is described.

  • Organizational Affiliation

    Department of Crystallography, University of Pittsburgh, PA 15260, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
A, B
226Escherichia coliMutation(s): 0 
Find proteins for P0AEQ3 (Escherichia coli (strain K12))
Explore P0AEQ3 
Go to UniProtKB:  P0AEQ3
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP0AEQ3
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.30 Å
  • R-Value Free: 0.289 
  • R-Value Work: 0.203 
  • R-Value Observed: 0.203 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 86.3α = 90
b = 86.3β = 90
c = 81.5γ = 90
Software Package:
Software NamePurpose
XENGENdata reduction
XENGENdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1996-11-08
    Type: Initial release
  • Version 1.1: 2008-03-24
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2024-02-07
    Changes: Data collection, Database references