1SA8

THE NMR STRUCTURE OF A STABLE AND COMPACT ALL-beta-SHEET VARIANT OF INTESTINAL FATTY ACID-BINDING PROTEIN


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 20 
  • Conformers Submitted: 10 
  • Selection Criteria: structures with the lowest energy 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

The NMR structure of a stable and compact all-beta-sheet variant of intestinal fatty acid-binding protein.

Ogbay, B.Dekoster, G.T.Cistola, D.P.

(2004) Protein Sci. 13: 1227-1237

  • DOI: 10.1110/ps.03546204

  • PubMed Abstract: 
  • Intestinal fatty acid-binding protein (I-FABP) has a clam-shaped structure that may serve as a scaffold for the design of artificial enzymes and drug carriers. In an attempt to optimize the scaffold for increased access to the interior-binding cavity ...

    Intestinal fatty acid-binding protein (I-FABP) has a clam-shaped structure that may serve as a scaffold for the design of artificial enzymes and drug carriers. In an attempt to optimize the scaffold for increased access to the interior-binding cavity, several helix-less variants of I-FABP have been engineered. The solution-state NMR structure of the first generation helix-less variant, known as Delta17-SG, revealed a larger-than-expected and structurally ill-defined loop flanking the deletion site. We hypothesized that the presence of this loop, on balance, was energetically unfavorable for the stability of the protein. The structure exhibited no favorable pairwise or nonpolar interactions in the loop that could offset the loss of configurational entropy associated with the folding of this region of the protein. As an attempt to generate a more stable protein, we engineered a second-generation helix-less variant of I-FABP (Delta27-GG) by deleting 27 contiguous residues of the wild-type protein and replacing them with a G-G linker. The deletion site of this variant (D9 through N35) includes the 10 residues spanning the unstructured loop of Delta17-SG. Chemical denaturation experiments using steady-state fluorescence spectroscopy showed that the second-generation helix-less variant is energetically more stable than Delta17-SG. The three-dimensional structure of apo-Delta27-GG was solved using triple-resonance NMR spectroscopy along with the structure calculation and refinement protocols contained in the program package ARIA/CNS. In spite of the deletion of 27 residues, the structure assumes a compact all-beta-sheet fold with no unstructured loops and open access to the interior cavity.


    Organizational Affiliation

    Department of Chemistry, Washington University School of Medicine, St. Louis, Missouri 63110, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Fatty acid-binding protein, intestinal
A
106Rattus norvegicusMutation(s): 0 
Gene Names: Fabp2 (Fabpi)
Find proteins for P02693 (Rattus norvegicus)
Go to UniProtKB:  P02693
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 20 
  • Conformers Submitted: 10 
  • Selection Criteria: structures with the lowest energy 
  • Olderado: 1SA8 Olderado

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2004-06-08
    Type: Initial release
  • Version 1.1: 2008-04-29
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance